题解 | #整数和#

#include<stdio.h>
int main(){
    int loop = 0;
    scanf("%d",&loop);
    while(loop--){
        int x = 0,y = 0;
        scanf("%d",&x);
        int flag = 1;
        if( x < 0 ){
            flag = -1;
            x *= -1;
        }
        y = (3*x)*(x+1)/2;
        printf("%d\n",flag * y);
    }
}