# Sum of n numbers in C

Sum of n numbers in C: This program adds n numbers which will be entered by a user. The user will enter a number indicating how many numbers to add and then the user will enter n numbers. We can do this by using or without using an array.

## C program to sum n numbers using a for loop

#include <stdio.h>

int main()
{
int n, sum = 0, c, value;

printf(“How many numbers you want to add?\n);
scanf(“%d”, &n);

printf(“Enter %d integers\n, n);

for (c = 1; c <= n; c++)
{
scanf(“%d”, &value);
sum = sum + value;
}

printf(“Sum of the integers = %d\n, sum);

return 0;
}

You can use long int or long long data type for the variable sum.

Output of program:

## C program to calculate sum of n numbers using an array

#include <stdio.h>

int main()
{
int n, sum = 0, c, array[100];

scanf(“%d”, &n);

for (c = 0; c < n; c++)
{
scanf(“%d”, &array[c]);
sum = sum + array[c];
}

printf(“Sum = %d\n, sum);

return 0;
}

The advantage of using an array is that we have a record of the numbers entered and can use them further in the program if required but storing them requires additional memory.

### C program for addition of n numbers using recursion

#include <stdio.h>

long calculate_sum(int [], int);

int main()
{
int n, c, array[100];
long result;

scanf(“%d”, &n);

for (c = 0; c < n; c++)
scanf(“%d”, &array[c]);

result = calculate_sum(array, n);

printf(“Sum = %ld\n, result);

return 0;
}

long calculate_sum(int a[], int n) {
static long sum = 0;

if (n == 0)
return sum;

sum = sum + a[n1];

return calculate_sum(a, n);
}