题解

#include <iostream>
#include <iomanip>
#include <algorithm>
using namespace std;

int main() {
    double x1, y1, x2, y2;
    double x3, y3, x4, y4;
    
    // 
    cin >> x1 >> y1 >> x2 >> y2;
    cin >> x3 >> y3 >> x4 >> y4;
    
    double minX1 = min(x1, x2);
    double maxX1 = max(x1, x2);
    double minY1 = min(y1, y2);
    double maxY1 = max(y1, y2);
    
    double minX2 = min(x3, x4);
    double maxX2 = max(x3, x4);
    double minY2 = min(y3, y4);
    double maxY2 = max(y3, y4);
    
    double overlapLeft = max(minX1, minX2);
    double overlapRight = min(maxX1, maxX2);
    double overlapBottom = max(minY1, minY2);
    double overlapTop = min(maxY1, maxY2);
    
    double area = 0.0;
    if (overlapLeft < overlapRight && overlapBottom < overlapTop) {
        area = (overlapRight - overlapLeft) * (overlapTop - overlapBottom);
    }
    
    cout << fixed << setprecision(2) << area << endl;
    
    return 0;
}