C Programming Assignments with Answers (21 Questions)

The following programs were solved by various friends. Hence if there are any mistakes/bugs/errors in the program kindly comment on at the end of the Post. We will try to rectify it. For downloading all the programs in a single PDF file: click this link https://engineeringcourses.files.wordpress.com/2010/12/clip_image022_thumb1.jpg2010/12/c-programming-assignments-with-answers-21-questions.html

Question 1

The straight line method of computing the yearly depreciation of the value of an item is given by

Depreciation = (Purchase Price – Salvage Value) / years of service.

Write a program to determine the salvage value of an item when the purchase price, years of service and the annual depreciation are given.

Program #include<stdio.h> #include<conio.h> int main() { int yr; float price,dep,salvalue; printf("enter the purchase price,years of service, annual depreciation"); scanf(" %f %d %f", &price,&yr,&dep); salvalue = price-(dep*yr); printf("The salvage value of the item is %f",salvalue); getch(); return 0; } Output: enter the purchase price, years of service, annual depreciation 5000 8 5.25 The salvage value of the item is 4958.000000

Question 2

Write a function exchange to interchange the values of two variables, say x and y. Illustrate the use of this function, in a calling function. Make x and y as global variables.

Program: #include<stdio.h> #include<conio.h> void exchange(int a,int b); void exchange(int a,int b) {int c; c=a; a=b; b=c; printf("the I no is …….%d \n the second no. is…….%d",a,b); } int main() {int x,y; printf("enter two no’s…..\n first no is…\n"); scanf("%d",&x); printf("enter second number….."); scanf("%d",&y); exchange(x,y); getch(); return 0; } Output: enter two no’s….. first no is… 5 enter second number…..9 the I no is …….9 the second no. is…….5

Question 3

Write a function space(x) that can be used to provide a space of x positions between two output numbers.

Program: #include<stdio.h> #include<conio.h> / /The two output numbers here are 0 and 1 void space(int); int main() { int x; printf("Enter the number of spaces between the two numbers: "); scanf("%d", &x); space(x); getch(); return 0; } void space(int x) { int i; printf("0"); for(i=0;i<x;i++) printf(" "); printf("1"); } Output:

Question 4

Write a function prime that returns 1 if its argument is a prime number and returns zero otherwise.

Program: #include<stdio.h> #include<conio.h> int prime(int); int main() { int res,num; printf("Enter a number to check if it is prime or not: "); scanf("%d", &num); res=prime(num); if(res==1) printf("\nThe number %d is prime\n", num); if(res==0) printf("\nThe number %d is not prime\n", num); getch(); return 0; } int prime(int n) { int i; for(i=2;i<=n/2;i++) {if(n%i==0) return 0;} return 1; } Output:

Question 5

Where u is the initial velocity (m/s), a the acceleration due to gravity (m/s2). Write a program to evaluate the distance travelled at regular intervals of time, given the values of u and a. the program should provide the flexibility to the user to select his own time intervals and repeat the calculations of different values of u and a

Program: #include<stdio.h> #include<conio.h> int main() { int s=0,d,u,a,t; while (1) { printf("\nenter initial velocity"); scanf("%d",&u); printf("\nenter the value of accceleration "); scanf("%d",&a); printf("\nenter time duration"); scanf("%d",&t); d = (a*t*t)/2; s=u+d; printf("\nthe distance covered is %d\n",d); } getch(); } Output:

Question 6

Write a program using for loops to produce a triangle using the asterisk (*) symbol. The program should prompt the user for the height of the triangle and check to see that the user entered a number greater than or equal to 3 and less than or equal to 40. If the user enters an invalid number, the program will print an error message and exit. If the user enters a valid number the program will print an equilateral triangle of height n, where n is the number the user entered at the console. The program should be written using no more than three printf() statements.

#include<stdio.h> #include<conio.h> int main() { int i, j, h; printf("Enter the height of the triangle : "); scanf("%d",&h); if((h>=3)&&(h<=40)) { for(i=1; i<=h; i++) { printf("\n"); for(j=1; j<=i; j++) { printf("* "); } } } else printf("\n\n\n\nError…..!!!!\n\n\n\nPress any key to exit…"); getch(); return 0; } OUTPUT SCREEN

Question 7

For an certain electrical circuit with an inductance L and resistance R, the damped natural frequency is given by

√(1/LC – R2/4C2). It is desired to study the variation of this frequency with C (capacitance). Write a program to calculate the frequency for different values of C starting from 0.01 to 0.1 in steps of 0.01.

#include<stdio.h> #include<conio.h> #include<math.h> int main() { float C[10] = { 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10 }; float R, L, f[10]; int i; printf("Enter the value of R : "); scanf("%f",&R); printf("\n\nEnter the value of L : "); scanf("%f",&L); for(i=0; i<10; i++) { f[i] = sqrt(1/(L*C[i])-(R*R)/(4*C[i]*C[i])); } printf("\n\n\nValue of C\tValue of f\n\n"); for(i=0; i<10; i++) { printf("%f\t%f\n",C[i],f[i]); } getch(); return 0; } OUTPUT SCREEN

Question 8

Write a program to determine and print the sum of the following harmonic series for a given value of n:

1 + ½ + 1/3 + ¼ +….. +1/n

The value of n should be given interactively through the terminal

Program: #include <stdio.h> int main() { int n; float a,i; printf("Input \t\t: "); scanf("%d", &n); while (!(n>0)) { printf("\n\nEnter a POSITIVE Number : "); scanf("%d", &n); } for (i=1; i<=n; i++) { a += (1.0/i); } printf("\nRequired Output : %f\n", a); return 1; } Output:

Question 9

Write a program that prompts the user for the number of Fibonacci numbers to generate and then prints the Fibonacci numbers to the screen. The user will enter some number, which we’ll call n. Your program should use a for loop to generate the Fibonacci numbers up to n, and then use a while loop to generate the numbers from n back down to zero.

#include<conio.h> #include<stdio.h> int main() { int i, n , fb[100]; fb[0]=0; fb[1]=1; printf("Enter a number till which you wish to print the series : "); scanf("%d",&n); printf("\n\n"); for(i=2; i<n; i++) { fb[i]=fb[i-1]+fb[i-2]; } for(i=0; i<n; i++) { printf("%d\t",fb[i]); } printf("\n\n\n\nReverse Order….\n\n"); i=n-1; while(i>=0) { printf("%d\t",fb[i]); i–; } getch(); return 0; } OUTPUT SCREEN

Question 10

Write a program to read the price of an item in decimal form (Eg 18.75) and print the output in paise like (1875).

Program: #include<stdio.h> #include<conio.h> int main() { printf("\t\t\t\t Program No. 10\n"); float rs,pais; printf("Enter the price of an item in rupees\n"); scanf("%f",&rs); pais = rs*100; printf("The price in paise is : %7.0f",pais); getch(); return 0; } Output: Program No. 10 Enter the price of item in rupees 187.5 The price in paise in : 18750

Question 11

A cloth showroom has announced the following seasonal discounts on purchase of items

Purchase Amount	Discount
Mill Cloth	Handloom Items
0-100	–	5%
101-200	5%	7.5%
201-300	7.5%	10.0%
301 and above	10%	15.0%

Write a program using switch and if statement to compute the net amount paid by a customer.

Program: #include<conio.h> #include<stdio.h> int main() { int choice; float price,total; printf("enter the choice of cloth and the price \n 1.mill cloth or \n 2. for handloom items"); scanf("%d %f",&choice,&price); switch(choice) { case 1:if (price>=0 && price<=100) total=price; else if (price>=101 && price<=200) total=price-(0.05*price); else if (price>=201 && price<=300) total=price-(0.075*price); else if (price>=301) total=price-(0.10*price); break; case 2:if (price>=0 && price<=100) total=price-(0.05*price); else if (price>=101 && price<=200) total=price-(0.075*price); else if (price>=201 && price<=300) total=price-(0.1*price); else if (price>=301) total=price-(0.15*price); break;} printf("the total is %f",total); getch(); return 0; } Output:

Question 12

Write a program that will read the value of x and evaluate the following function.

Y=1 for x >0

Y=0 for x=0

Y=-1 for x< 0

Using (a) nested if statements (b) else if statements (c) conditional Operator

Program: #include <stdio.h> #include <conio.h> int main() { float x,y; printf("Enter thhe value of X="); scanf("%f",&x); if (x>0) printf("Y=1"); else if (x==0) printf("Y=0"); else if(x<0) printf("Y=-1"); getch(); return 0; } Output: Enter the value of X=6 Y=1

Question 13

A number is special if it is divisible by 15. A number is big if it is greater than 999. A number is weird if it is divisible by 5 and 6 but not 18. A number is scary if it is big or weird. Declare four variables called special, big, weird and scary and make suitable assignments to these variables as a number is tested.

Program: #include<stdio.h> #include<conio.h> int main() { int n,special,big,weird,scary; printf("enter a no."); scanf("%d",&n); if(n%15==0) { special=n; printf("%d is a special no\n",special); } if (n>999) { big=n; printf("%d is a big no\n",big); } if(n%5==0 && n%6==0 && n%18!=0) { weird=n; printf("%d is a weird no.\n",weird); } if(n==big || n==weird) { scary=n; printf("%d is a scary no\n",scary); } getch(); return 0; } Output: Enter a no. 1500 1500 is a special no 1500 is a big no 1500 is a weird no 1500 is a scary no

Question 14

Declare two arrays A and B, find A n B and A u B.

Program: #include<stdio.h> #include<conio.h> int main() {int n; printf("enter the size of the array"); scanf("%d",&n); int a[n],b[n]; printf("enter elements of I array"); for(int i=0;i<n;i++) {scanf("%d",&a[i]);} printf("enter elements of II array"); for(int j=0;j<n;j++) {scanf("%d",&b[j]);} printf("the intersection of two arrays are"); for(int i=0;i<n;i++) {for(int j=0;j<n;j++) {if(a[i]==b[j]){printf("%d",b[j]); }}} printf("\n"); printf("the union of two arrays is\n"); for(int i=0;i<n;i++) { printf("%d",a[i]); } for(int j=0;j<n;j++) {int var=0; for(int i=0;i<n;i++) { if(b[j]==a[i]) {var=var+1;} } if(var==0) {printf("%d",b[j]);} } getch(); return 0; } Output: enter the size of the arrays 5 enter elements of I array 7 8 9 5 4 enter elements of II array 8 9 2 3 6 the intersection of two arrays are89 the union of two arrays is 78954236

Question 15

Write a program to, reverse a given array

Program: #include <stdio.h> #include <conio.h> int main() { int n,p; printf("Enter size of array \n"); scanf("%d", &n); int a[n],i,t; printf("Enter elements of array \n"); for(i=0;i<n;i++) scanf("%d",&a[i]); i=0; p=n; while(i<=n/2) { t=a[i]; a[i]=a[n-1]; a[n-1]=t; i++; n–; } printf("Reversed array \n"); for(i=0;i<p;i++) printf("%d ",a[i]); getch(); return 0; } Output: Enter the size of array4 Enter elements of array1 3 7 4 Reversed array 4 7 3 1

Question 16

Search an element in an array and display the index position of all the elements of that value.

Program:- #include<conio.h> #include<stdio.h> int main() { int i,n=0,ans=0,s=0; double a[100],ele; char t; while(n<=0||n>100) { printf("enter the number of elements(max 100)\n"); scanf("%d",&n); } for(i=0;i<n;i++) { printf("enter the value of element"); printf(" %d\n",i+1); scanf("%lf",&a[i]); } do { printf("enter the element you want to search\n"); scanf("%lf",&ele); s=0; for(i=0;i<n;i++) { if(a[i]==ele) {printf("the element is found at position %d\n",i+1); s+=1;} } if(s==0) { printf("the element is not found\n"); } printf("enter 1 to search more or any key to exit\n"); t=getch(); ans = t-48; }while(ans==1); return 0; } Output:

Question 17

Perform the matrix multiplication using two dimensional array by sending entire array to a function mmultiply()

#include<stdio.h> #include<conio.h> void multiply(int a[][],int b[][]); int main() { int a[3][3],b[3][3],c[3][3]; int i,j; printf("matrix a:"); for(i=0;i<3;i++) { for(j=0;j<3;j++} scanf("%d",&a[i][j]); } printf("matrix b:"); for(i=0;i<3;i++) { for(j=0;j<3;j++} scanf("%d",&b[i][j]); } multiply(a[][],b[][]); getch(); return 0; } void multiply(int a[][],int b[][]) { int i,j,k; for(i=0;i<3;i++) { for(j=0;j<3;j++) { c[i][j]=0; for(k=0;k<n;k++) { c[i][j]=c[i][j]+a[i][k]*b[k][j]; } } } printf("resultant matrix:"); for(i=0;i<3;i++) { for(j=0;j<3;j++} scanf("%d",&c[i][j]); } } OUTPUT:- Matrix a:0 1 2 2 3 4 3 4 5 Matrix b:0 1 2 2 3 4 3 4 5 Resultant matrix:6 13 16 18 31 40 23 40 52

Question 18

Write a program to calculate the standard deviation of an array of values. The array elements are read from the terminal. Use functions to calculate standard deviation and mean.

#include<stdio.h> #include<conio.h> #include<math.h> int main() { int n; printf("Enter how many numbers you want to enter?"); scanf("%d",&n); int a[n]; printf("enter the numbers"); double x=0.0,x1=0.0; int i; double z; for(i=0;i<n;i++) { scanf("%d",&a[i]); x=x+a[i]; } x=x/n; for(i=0;i<n;i++) { x1=x1+pow((x-a[i]),2); } z=sqrt(x1/n); printf("standard deviation is %f",z); getch(); return 0; }

Question 19

An election is contested by 5 candidates. The candidates are numbered 1 to 5 and the voting is done by marking the candidate number on the ballot paper. Write a program to read the ballots and count the votes cast for each candidate using an array variable count. In case, a number read is outside the range 1 to 5, the ballot should be considered as a spoilt ballot and the program should also count the number of spoilt ballots.

#include<conio.h> #include<stdio.h> int main() { int i, vote[100], c1=0, c2=0, c3=0, c4=0, c5=0, c_spoilt=0, n; printf("Enter the number of voters : "); scanf("%d",&n); printf("\n\n\n\n\nEnter votes ( between 1 to 5 )….\n\n\n\n"); for(i=0; i<n; i++) { printf("\nVoter %d : ",i+1); scanf("%d", &vote[i]); if((vote[i]<=5)&&(vote[i]>=1)) { switch(vote[i]) { case 1 : c1++; break; case 2 : c2++; break; case 3 : c3++; break; case 4 : c4++; break; case 5 : c5++; break; default : printf("Error…!!!"); } } else { vote[i]=0; c_spoilt++; } } printf("\n\n\n\nNumber of votes for candidate 1 : %d", c1); printf("\n\nNumber of votes for candidate 2 : %d",c2); printf("\n\nNumber of votes for candidate 3 : %d",c3); printf("\n\nNumber of votes for candidate 4 : %d",c4); printf("\n\nNumber of votes for candidate 5 : %d",c5); printf("\n\nNumber of votes spoilt : %d",c_spoilt); getch(); return 0; } OUTPUT SCREEN

Question 20

Define a structure called cricket that will describe the following information:

Player name, team name, batting average.

Using cricket, declare an array player with 10 elements and write a program to read the information about all the 50 players and print a team wise list containing names of players with their batting average.

Program: #include<stdio.h> #include<conio.h> #include<string.h> struct cricket { char playername[50]; char teamname[50]; float battingavg; }; int main() { struct cricket player[100]; int i,n,m,j; char name[10][10]; printf("Enter the no. of teams:- "); scanf("%d",&n); for(j=0;j<n;j++) { printf("Enter the name of the teams:- "); scanf("%s",&name[j]); } printf("\nEnter the no. of players:- "); scanf("%d",&m); for(i=0;i<m;i++) { printf("Enter the %d player name, team name & batting avg:- ",i+1); scanf("%s%s%f",&player[i].playername,&player[i].teamname,&player[i].battingavg); } printf("\n\nListing according to team names::\n"); for(j=0;j<n;j++) { printf("\n%s-\n",name[j]); for(i=0;i<m;i++) { if(strcmp(player[i].teamname,name[j])==0) { printf("\t%s\t%f\n",player[i].playername,player[i].battingavg); } } } getch(); return 0; } Output: Enter the no. of teams:- 2 Enter the name of the teams:- TEAM1 Enter the name of the teams:- TEAM2 Enter the no. of players:- 4 Enter the 1 player name, team name & batting avg:- A TEAM1 41 Enter the 2 player name, team name & batting avg:- B TEAM2 23 Enter the 3 player name, team name & batting avg:- C TEAM1 15 Enter the 4 player name, team name & batting avg:- D TEAM2 45 Listing according to team names:: TEAM1- A 41.000000 C 15.000000 TEAM2- B 23.000000 D 45.000000

Question 21

A bookshop uses a personal computer to maintain the inventory of books that are being sold at the shop. The list includes details such as author, title, isbn number, price, author, stock position. Whenever a customer wants a book, the shopkeeper inputs the title or isbn number and the system replies whether the book is available or not. If it is not, an appropriate message is displayed. If book is in the list, then the system displays the book details and asks for number of copies. If the requested copies are available, the total cost of the books is displayed, otherwise the message “Requested copies are not in stock” is displayed. Implement using structures.

#include<conio.h> #include<stdio.h> #include<string.h> struct book { char author[50]; char title[50]; int isbn_num, stock, price; }; int main() { char search[20]; char t1[50]; int i, n, n1, copies, bill; struct book b1[100]; printf("Enter the number of book records you want to enter : "); scanf("%d", &n); printf("\n\n\nEnter the records…\n\n\n"); for(i=0; i<n; i++) { printf("\nEnter the record number %d…\n",i+1); printf("\nName of the author : "); gets(b1[i].author); printf("\nTitle of the book : "); gets(b1[i].title); printf("\nIsbn number : "); scanf("%d", &b1[i].isbn_num); printf("\nStock : "); scanf("%d", &b1[i].stock); printf("\nPrice : "); scanf("%d", &b1[i].price); } printf("\n\n\n\nWhat do you want to enter for search ( Title / Isbn ) ?\n\n"); scanf("%s",search); if(strcmpi("title",search)==0) { printf("\n\nTitle of the book you wish to search : "); gets(t1); for(i=0; i<n; i++) { if( strcmpi(b1[i].title,t1)==0) { printf("\nTitle : "); puts(b1[i].title); printf("\nAuthor : "); puts(b1[i].author); printf("\nIsbn Number : %d",b1[i].isbn_num); printf("\nStock : %d",b1[i].stock); printf("\nPrice : %d",b1[i].price); printf("\n\nNumber of copies you want of the book : "); scanf("%d",&copies); if(copies<=b1[i].stock) { bill = copies*b1[i].price; printf("\nTotal price : Rs. %d", bill); } else printf("\n\nRequested copies are not in stock…!!!"); } else printf("\n\nRequested book not available…!!!"); } } else if(strcmpi("isbn",search)==0) { printf("\n\nIsbn Number of the book you wish to search : "); scanf("%d",&n1); for(i=0; i<n; i++) { if(b1[i].isbn_num==n1) { printf("\nTitle : %s", b1[i].title); printf("\nAuthor : %s", b1[i].author); printf("\nIsbn Number : %d",b1[i].isbn_num); printf("\nStock : %d",b1[i].stock); printf("\nPrice : %d",b1[i].price); printf("\n\nNumber of copies you want of the book : "); scanf("%d",&copies); if(copies<=b1[i].stock) { bill = copies*b1[i].price; printf("\nTotal price : Rs. %d", bill); } else printf("\n\nRequested copies are not in stock…!!!"); } else printf("\n\nRequested book not available…!!!"); } } getch(); return 0; } OUTPUT SCREEN

C Programming Assignments with Answers (21 Questions)

Please click the following link to download the PDF File which contains the 21 C Programs that were solved by various friends.

Assignment_answer

Lecture Notes on C Programming

Download the lecture notes on C programming by clicking the following link.

CProgramming

String handling functions in C

Like numbered arrays, C handles character arrays (strings).

1. Each string is identified as a character array and ends with a ‘’(null) character (the compiler automatically adds the null character). So the end of string is identified as a null character.
2. Being an array, all the elements of the string array stored in continuous memory locations

following is the declaration of character array

char name[50];

or

char name[]=”Pradeep Kumar”;

or

char name[20]=”Hello Pradeep”;

Strings can be handled or manipulated through loops or library functions. There are some library functions to handle strings are available at string.h

Some of them are

strlen(string) 

• This is to find the length of the string and returns an integer
• For example, if “Hello” is the string, the length will be 5 and “Hello “, the length is 6 (there is a blank space after o in hello)

strcat(String1, string2)

• to concatenate two strings
• One string will be appended to another string (the concatenation happens by inserting the new string at the null character ‘’ of the first string)
• Example, if String1 is “Hello” and String2 is “Pradeep”, then strcat(string1, string2) will be “HelloPradeep”
• Similarly,  if String1 is “Hello ” and String2 is “Pradeep”, then strcat(string1, string2) will be “Hello Pradeep”

strcpy(Destination, source)

• This function is to copy one string to other
• usually the copying string will be the 2nd parameter and copied string will be the first parameter
• Example, if string1 is “Bad” and string2 is “Good” the strcpy(string1,string2) will give Good for string1

strcmp(Destination, source)

• This function is to compare two strings whether they are equal or not
• like numbers, two strings should not be compared directly like if(a==b)
• If both the strings are equal, the function returns 0, else it will return the difference of ASCII value of the first non matching characters
• Example, strcmp(“Their”, “There”) will return ASCII(i) – ASCII(r) (an integer will be returned)

Example Program

//program to demonstrate string handling functions
#include <stdio.h>
#include <conio.h>
int main()
{
    char a[50];
    char b[50];
    printf("Please the two strings one by one\n");
    gets(a);
    gets(b);
    printf("Length of String a is %d \n",strlen(a));
    printf("Length of String b is %d \n",strlen(b));
    if(!strcmp(a,b))  //Comparing two string will return 0, ! before strcmp() is needed
    printf("Both the strings are Equal");
    else
    printf("Both the strings are not equal");
    strcat(a,b);  //Concatenation function
    printf("the concatenated String is:");
    puts(a);
    strrev(a);
    printf("The reverse string is\n");
    puts(a);
    getch();
    return 0;
}
   
   

In the above program , instead of gets() function, scanf() can be used, but the disadvantage of scanf() being it truncates the blank space, new line, form feed, tab.

So for example, if the input give is “Hello pradeep”, then Hello only will be accepted, the string after the blank space will be omitted by the compiler, so gets() can be used.

Similarly, puts() or printf() can be used to display strings.

Passing entire structure to a function

1. A function can accept a structure as a parameter and even it returns a parameter too.
2. Either the individual structure elements can be passed or the entire structure can be passed.

Here is the example, for passing the entire structure to a function

#include <stdio.h>
#include <conio.h>

//Structure declaration

struct student
{
char name[10];
int no;
};

//Function prototypes

void read(struct student);
struct student display(struct student); //function which takes the entire structure as a parameter and it returns a structure also

int main()
{
    struct student s1,s;
     printf("Enter the details");
    scanf("%s %d",s1.name,&s1.no);
    s=display(s1);  //function call
printf("Name is %s and number is %d",s.name,s.no);
    getch();
}

//Function definition

struct student display(struct student s)
{
return s;
}

Nested Structures

A structure can be declared within another structure.

Example include: for a student structure maintaining the date of birth is tougher within the structure,

to avoid the complexity, dateofbirth can be a separate structure as defined below

struct dateofbirth
{
int date;
int month;
int year;
};

struct student
{
char name[50];
int no;
struct dateofbirth dob;
};

so the structure can be accessed using the following:

s.dob.date, s.dob.month, s.dob.year, and s.name, s.no

Example of Nested Structures

 

#include <stdio.h>
#include <conio.h>

//declare the structure dateofbirth which holds date,month and year

struct dateofbirth
{
int date;
int month;
int year;
};

//declare another structure student which also includes dateofbirth as a datatype

struct student
{
char name[50];
int no;
struct dateofbirth dob; //from another structure
};

int main()
{
struct student s;
printf("Enter the name number and date of birth (dd/mm/yyyy)");
scanf("%s %d %d/%d/%d",s.name,&s.no,&s.dob.date,&s.dob.month,&s.dob.year);
printf("%s %d %d/%d/%d",s.name,s.no,s.dob.date,s.dob.month,s.dob.year);
getch();
return 0;
}

It is always nice to include nested structures in applications as good readability is provided

for Example: building.concrete.cement.quality

Structures in C Programming

1. Structure in C groups different data type under a common name
2. struct is a keyword to declare a structure
3. The size of the structure depends on the size of the different data types
4. Structure declaration always ends with a semicolon

Example:

struct employee

{

char name[50];

int empid;

float salary;

};

The total size occupied by the above structure is 50 + 2 + 4 = 56 bytes (on TC compiler) and 50 + 4 + 4= 58 (on other compilers like GCC, etc). Again the size depends on the compiler.

GCC compiler always increase the size of structure which is divisible by 4 for faster code generation, so the above structure takes 60 bytes of memory

1. Declaring a structure does not consume any memory, only when the structure object is created memory occupies
2. Variables initialization will not be done during the structure declaration

The above syntax declaration does not consume memory, but the following do

int main()

{

struct employee e1;

}

Now e1 consumes memory of 60 bytes.

Simple Structure to get some details and print them to the screen

// GCC Compiler under windows 64bit

#include <stdio.h>
#include <conio.h>

/*  structures are declared outside any functions,
so that all the functions in the program can have access to it
*/
struct employee
{
       char name[50];
       int empid;
       float salary;
};

int main()
{
    struct employee e1;
    printf("enter the name, id and salary");
    scanf("%s %d %f",e1.name, &e1.empid, &e1.salary); 

    printf("The details entered are \n");
    printf("%s %d %f",e1.name, e1.empid, e1.salary);
    getch();
    return 0;
}

In the above program name, empid and salary are part of employee, so it should be associated with the member of structure, that’s why e1.name, e1.empid and e1.salary.

 

Array of Structures

//the following program gets the inputs of 3 employees like name, id and salary and compute the total salary taken by all the employees

#include <stdio.h>
#include <conio.h>

/*  structures are declared outside any functions,
so that all the functions in the program can have access to it
*/
struct employee
{
       char name[50];
       int empid;
       float salary;
};

int main()
{
    struct employee e[3];
    int i;
    float sum=0;
    printf("enter the name, id and salary");
    for(i=0;i<3;i++)
    {
    scanf("%s %d %f",e[i].name, &e[i].empid, &e[i].salary);
    sum=sum+e[i].salary;
    }
   
   
    printf("The details entered are \n");
    for(i=0;i<3;i++)
    printf("%s %d %f",e[i].name, e[i].empid, e[i].salary);
    printf("Total Salary of all 3 employees is %f",sum);
    getch();
    return 0;
}

Sample Output

 

Arrays within Structures

//The following program gets the 2 student inputs like 3 subject marks and compute the total of all three subject marks

#include <stdio.h>
#include <conio.h>

/*  structures are declared outside any functions,
so that all the functions in the program can have access to it
*/
struct student
{
       int subjects[3];
       float total;
};

int main()
{
    struct student s[2];
    int i,j;

    printf("enter the 3 subject marks");
    for(i=0;i<2;i++)
    {
    s[i].total=0;
    for(j=0;j<3;j++)
    {
    scanf("%d",&s[i].subjects[j]);
    s[i].total += s[i].subjects[j];
    }
    printf("The total marks scored by student%d is %f",i+1,s[i].total);
    }
   
    getch();
    return 0;
}

Sample Output

Workshop on MEMS at VIT University–Chennai Campus

 

C Program–Multiplying two matrices

/* Program to multiply two matrices */

#include <stdio.h>
#include <conio.h>
int main()
{
    int a[2][3],b[3][2],c[2][2],k,j,i;
    printf("enter a");
    for(i=0;i<2;i++)   //Get array A
    {
    for(j=0;j<3;j++)
    {
    scanf("%d",&a[i][j]); 
    }
    }
    printf("enter b");
    for(i=0;i<3;i++) //Get array B
    {
    for(j=0;j<2;j++)
    {
    scanf("%d",&b[i][j]);
    }
    }

    for(i=0;i<2;i++) 
    {
    for(j=0;j<2;j++)
    {
    c[i][j]=0;  //to Hold a temporary multiplication
    for(k=0;k<3;k++)
    {
    c[i][j]=c[i][j]+a[i][k]*b[k][j];   //Multiplication algorithm
    }
    }
    }
    printf("C is ");
    for(i=0;i<2;i++)
    for(j=0;j<2;j++)
    printf(" c[%d][%d] – %d \n",i,j,c[i][j]); 
 
getch();  
    return 0;
}

C Program–Adding two matrices

/* Program to add two matrices */

#include <stdio.h>
#include <conio.h>
int main()
{
    int a[10][10], b[10][10],c[10][10],i,j;
    printf("Enter a");
    for(i=0;i<2;i++)  //get the matrix A
        for(j=0;j<2;j++)
    scanf("%d",&a[i][j]);
    printf("Enter b");
    for(i=0;i<2;i++) //get the matrix B
        for(j=0;j<2;j++)
    scanf("%d",&b[i][j]);
   
    for(i=0;i<2;i++)
    {
        for(j=0;j<2;j++)
        {
        c[i][j] = a[i][j] +b[i][j];    //adding two matrices
        }
    }
    printf("Added Matrix is \n");
    for(i=0;i<2;i++)
        for(j=0;j<2;j++)
    printf("%d ",c[i][j]);
        getch();
        return 0;
}

How to interpret the NS2 tracefile (manually) for wireless simulation

Assume you created a tcl file for a wireless simulation and it generates a trace file (usually .tr as extension). If any tracing softwares are not available, how to interpret manually, here is the step

ACTION: [s|r|D]: s -- sent, r -- received, D – dropped

WHEN: the time when the action happened

 
WHERE: the node where the action happened

LAYER: AGT -- application, 

 RTR -- routing, 
 LL  -- link layer (ARP is done here)
 IFQ -- outgoing packet queue (between link and mac layer)
 MAC -- mac, 
 PHY – physical
 
 
flags:
 
SEQNO: the sequence number of the packet

 
TYPE: the packet type
  cbr -- CBR data stream packet
  DSR -- DSR routing packet (control packet generated by routing)
  RTS -- RTS packet generated by MAC 802.11
  ARP -- link layer ARP packet

SIZE: the size of packet at current layer, when packet goes down, size increases, goes up size decreases
[a b c d]: a -- the packet duration in mac layer header
  b -- the mac address of destination
  c -- the mac address of source
  d -- the mac type of the packet body

flags:
[......]: [
  source node ip : port_number
  destination node ip (-1 means broadcast) : port_number
  ip header ttl 
  ip of next hop (0 means node 0 or broadcast)
  ]

So we can interpret the below trace

s 0.0297823400 _1_ RTR --- 2012 cbr 32 [0 0 0 0] ------- [1:0 0:0 32 0]

as Application 0 (port number) on node 1 sent a CBR packet whose ID is 2012 and size is 32 bytes, at time 0.029 second, to application 0 on node 0 with TTL is 32 hops. The next hop is not decided yet.

And we can also interpret the below trace

r 0.010176954 _9_ RTR  --- 1 gpsr 29 [0 ffffffff 8 800] ------- [8:255 -1:255 32 0]

in the same way, as The routing agent on node 9 received a GPSR broadcast (mac address 0xff, and ip address is -1, either of them means broadcast) routing packet whose ID is 1 and size is 19 bytes, at time 0.010176954 second, from node 8 (both mac and ip addresses are 8), port 255 (routing agent).

This link has been taken for reference from http://ns-2.blogspot.com/2007/06/how-to-interprete-ns2-tracefile-for.html