C Program to calculate sum of numbers 1 to N using recursion

#include<stdio.h>
int calculateSum(int);
int main() {
   int i, num;
   int result;
   printf("Input a number : ");
   scanf("%d", &num);
   result = calculateSum(num);
   printf("\nSum of Number From 1 to %d : %d", num, result);
   return (0);
}
int calculateSum(int num) {
   int res;
   if (num == 1) {
      return (1);
   } else {
      res = num + calculateSum(num - 1);
   }
   return (res);
}

#include<stdio.h>

int calculateSum(int);

int main() {

int i, num;

int result;

printf("Input a number : ");

scanf("%d", &num);

result = calculateSum(num);

printf("\nSum of Number From 1 to %d : %d", num, result);

return (0);

}

int calculateSum(int num) {

int res;

if (num == 1) {

return (1);

} else {

res = num + calculateSum(num - 1);

}

return (res);

}

Output :

Input a number : 5
Sum of Number From 1 to 5 :15

1 2	Input a number : 5 Sum of Number From 1 to 5 :15

Table of Content

C Program to calculate sum of numbers 1 to N using recursion

Output :