C 程序 查找前 n 个自然数的和

#include <stdio.h>
int main()
{
    int n, count, sum = 0;

    printf("Enter the value of n(positive integer): ");
    scanf("%d",&n);

    for(count=1; count <= n; count++)
    {
        sum = sum + count;
    }

    printf("Sum of first %d natural numbers is: %d",n, sum);

    return 0;
}

Enter the value of n(positive integer): 6
Sum of first 6 natural numbers is: 21

#include <stdio.h>
int main()
{
    int n, count, sum = 0;

    printf("Enter the value of n(positive integer): ");
    scanf("%d",&n);

    /* When you use while loop, you have to initialize the
     * loop counter variable before the loop and increment
     * or decrement it inside the body of loop like we did 
     * for the variable "count"
     */
    count=1;
    while(count <= n){
        sum = sum + count;
        count++;
    }

    printf("Sum of first %d natural numbers is: %d",n, sum);

    return 0;
}

Enter the value of n(positive integer): 7
Sum of first 7 natural numbers is: 28