Program To Find Sum Of Digit

Some Basic C program frequently asked in Interview.

/* Program to find sum of digit of a number*/ 

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b,s=0;

clrscr();

printf("Enter a number:\t");

scanf("%d",&a);

while(a>0)

{

b=a%10;

s=s+b;

a=a/10;

}

printf("Sum of digit is %d",s);

getch();

}

Program To Convert a Number into Binary

Some Basic C program frequently asked in Interview.

/*Program to convert a number into Binary*/

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b;

clrscr();

printf("Enter a number:\t");

scanf("%d",&a);

printf("\t");                  //'\t' is for tab 

while(a>0)

{

b=a%2;

printf("%d",b);

printf("\b\b");         // '\b' is for backspace

a=a/2;

}

getch();

}

Program to check a prime number.

Some Basic C program frequently asked in Interview.

/* Program to check whether a number is prime or not*/

#include<stdio.h>

#include<conio.h>
void main()
{
int a,b;
clrscr();
printf("Enter a number:\t");
scanf("%d",&a);
b=2;
while(a%b!=0)
{
b++;
}
if(a==b)
{
printf("\n%d is prime number",a);
}
else printf("\n\t%d is not prime number",a);
getch();
}

Program to Calculate power of a number

Some Basic C program frequently asked in Interview.

/* Power of a Number*/

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b,c;

clrscr();

printf("Enter a number,and its power\t");

scanf("%d%d",&a,&b);

c=1;

while(b>=1)

{

c=c*a;

b--;

}

printf("%d",c);

getch();

}

Program To check a Number is Pallindrome & Armstrong

Some Basic C program frequently asked in Interview.

/*To check a number is pallindrome or not */

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b,c,s=0;

clrscr();

printf("Enter a number:\t");

scanf("%d",&a);

c=a;

//the number is reversed inside the while loop.

while(a>0)

{

b=a%10;

s=(s*10)+b;

a=a/10;

}

//Here the reversed number is compared with the given number.

if(s==c)

{

printf("The no. %d is a pallindrome",c);

}

else

printf("The no. %d is not a pallindrome",c);

getch();

}

/*To check a number is armstrong or not */

#include<stdio.h>

#include<conio.h>

void main()

{

int a,b,c,s=0;

clrscr();

printf("Enter a number:\t");

scanf("%d",&a);

c=a;

//Sum of cube of each digit of given  number is claculated inside the while loop.

while(a>0)

{

b=a%10;

s=s+b*b*b;

a=a/10;

}

//Sum is compared with the given number.

if(s==c)

{

printf("The no. %d is a armstrong no.",c);

}

else

printf("The no. %d is not a armstrong no.",c);

getch();

}

C program to replace multiple spaces with a single space

Program to replace multiple spaces between two words in a string by a single space

#include<stdio.h>

#include<conio.h>

void main()

{

char s[50];

char *str=s;

int i,j;

clrscr();

printf("Enter the String:\n");

gets(s);

for(i=0;*(str+i)!='\0';i++)

   {

   if(*(str+i)==' '&*(str+i+1)==' ')

   {

   for(j=i;*(str+j)!='\0';j++)

     {

 *(str+j)=*(str+j+1);

 }

 i--;

   }

   }

     printf("\n%s",str);

   getch();

}

Count number of words in a string

Program to count number of words in a string enter by a user 

#include<stdio.h>

#include<conio.h>

#include<string.h>

void askstring()

{

char str[50];

int i,words=0;

printf("\nEnter a string\n");

scanf("%[^\n]c",str);

//printf("\nThe String is: %s",str);

for(i=0;str[i]!='\0';i++)

{

if(str[i]==' ')

words++;

}

printf("\n Number of words in the stirng :%d",words+1);

}

void main()

{

clrscr();

askstring();

getch();

}

Frequently asked C programs

Some Basics C program frequently asked in interviews

1.Find factorial of a number using recursive function.

#include<stdio.h>

#include<conio.h>

int fact(int);

void main()

{

int a,b;

printf("Enter no.");

scanf("%d",&a);

clrscr();

b=fact(a);

printf("%d",b);

getch();

}

int fact(int x)

{

int r=1;

if(x==1) return 1;

else r=x*fact(x-1);

return r;

}

2. Getting a multiple word string having spaces from user using scanf function.

#include<stdio.h>

#include<conio.h>

void main()

{

char name[20];

printf("Enter name:\n");

scanf("%[^\n]s",&name);              /* notice the format specifier used here i.e 

%[^\n]s

*/

printf("%s",name);                          

getch();

}