Question

In C Programming Language:

Given an integer N, find whether the sum of the digits calculated repeatedly till a single digit is obtained results in the sum of 1 or not. Display 1 if the sum of the digits of N can equal 1 else display 0.

Example: For 199, Sum of digits = 1+9+9=19, 1+9=10, 1+0=1 so it should display 1

For 57, sum of digits = 5+7=12, 1+2=3 so it should display 0

Answer 1

#include<stdio.h>

int getResult(int N){
   int sum = 0;
   while(N>0){
      sum += (N%10);
      N = N / 10;
   }
   if(sum<10){
      return sum;
   }
   else{
      return getResult(sum);
   }
}

int main () {
   int N, res;
   
   printf("Enter value for N: ");
   scanf("%d",&N);
   
   res = getResult(N);
   
   if(res == 1){
      printf("1\n");
   }
   else{
      printf("0\n");
   }
   
   return 0;
}