Armstrong Number

C Program to Check Armstrong Number

#include<stdio.h>   
int main()
{   
   int a,b,sum=0;
   scanf("%d",&a);   
   int t=a;   
   while(a>0)   
   {   
    b=a%10;   
    sum=sum+(b*b*b);   
    a=a/10;   
   }   
    if(t==sum)   
       printf("Its an armstrong number");   
    else   
       printf("Not an armstrong number");   
    return 0;   

} 

Output:

153                                                                                                                   

Its an armstrong number

Sum of Digits

Sum of digits program in C

#include<stdio.h> 
int main()
{ 

    int a,b,sum=0;

    printf("Enter Number:");

    scanf("%d",&a); 

    while(a>0) 

    { 

        b=a%10; 

        sum=sum+b; 

        a=a/10; 

    } 

    printf("Sum is %d",sum);
    return 0; 

} 

Output:

Enter Number:123                                                                                                      

Sum is 6    

Sum of N numbers which are divisible by 5

Sum of N numbers which are divisible by 5 #include<stdio.h>
int main() {
int a,sum=0,i=1;
scanf("%d",&a);
while(i<=a)
{
if(i%5==0)
{
sum=sum+i;
}
i++;
}
printf("%d",sum);
return 0;
} Output: Enter Number:100                                                                                                       1050

Sum of N numbers

C Program to Calculate the Sum of Natural Numbers

Source Code :

#include<stdio.h> int main()  {    int a,sum=0,i=0;    printf("Enter number:");       scanf("%d",&a);    while(i<=a)    {      sum=sum+i;      i++;    }    printf("%d",sum);    return 0; }

Output:

Enter number:10                                                                                                       

55