c语言 6-5

c语言 6-5

#include <stdio.h>

int sumup(int n)
{
    int sum = 0;
    int i;
    for(i = 1; i <= n; i++)
    {
        sum += i;
    }
    return sum;
}

int main(void)
{
    int i;
    puts("please input an integer.");
    printf("i = "); scanf("%d", &i);
    
    printf("the sum =; %d
", sumup(i));
    return 0;
}

2、

#include <stdio.h>

int sumup(int a)
{
    int sum = 0;
    while(a > 0)
    {
        sum += a;
        a--;    
    } 
    return sum;
}

int main(void)
{
    int i;
    puts("please input an integer.");
    printf("i = "); scanf("%d", &i);
    
    printf("the result=: %d
", sumup(i));
    return 0;
}