有人讲解一下吗，没想出来

Question

Answer 1

#include<stdio.h>
#include<math.h>
int main()
{
    int n,k=1;
    scanf("%d",&n);
    while(n>=0){
        n-=k;
        k++;
    }
    printf("%d",abs(n));
}

觉得有用的话采纳一下哈