C语言练习：使用for循环或while循环求前n个自然数的和

1.For Loop

#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;
}

2.While Loop

#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;
}