蓝桥杯练习 矩形面积交（计算几何）

#include <cstdio>
#include <algorithm>
#define swap(a,b) {double t;t=a;a=b;b=t;}
using namespace std;
int main()
{
    double x[4], y[4];
    while (~scanf("%lf%lf", &x[0], &y[0])) {
        for (int i = 1; i < 4; i++) {
            scanf("%lf%lf", &x[i], &y[i]);
        }
        if (x[0] > x[1])
            swap(x[0], x[1]);
        if (x[2] > x[3])
            swap(x[2], x[3]);
        if (y[0] > y[1])
            swap(y[0], y[1]);
        if (y[2] > y[3])
            swap(y[2], y[3]);
        if (x[1] <= x[2] || x[0] >= x[3] || y[0] >= y[3] || y[1] <= y[2]) {
            printf("0.00\n");
            continue;
        }
        else {
            sort(x, x + 4);
            sort(y, y + 4);
            printf("%.2lf\n", (x[2] - x[1]) * (y[2] - y[1]));
        }
    }
    return 0;
}