为什么程序会不断输出“矩形不重叠”？

Question

我试图弄清楚为什么不管输入的int值是哪种类型，该程序始终输出Rectangles Do Not Overlap。

我已经尝试在if函数中修复我的isRectangleOverlap()语句，但由于某些原因，输出仍然保持不变。

一个矩形表示为列表[x1，y1，x2，y2]，其中（x1，y1）是其左下角的坐标，而（x2，y2）是其右上角的坐标。

它不输出以下示例：

示例1：输入：rec1 = [0,0,2,2]，rec2 = [1,1,3,3]输出：矩形重叠

示例2：输入：rec1 = [0,0,1,1]，rec2 = [1,0,2,1]输出：矩形不重叠

要清楚，两个仅在角或边缘接触的矩形不重叠。

#include <iostream>
#include <vector>
using namespace std;

struct Point{
    int x, y;
};

bool isRectangleOverlap(Point t1, Point b1, Point t2, Point b2){

    if ((t1.x <= t2.x && b2.x <= b1.x) && (t1.y >= t2.y && b2.y >= b1.y)) {
        return true;
    }
    else if ((t2.x <= t1.x && b1.x <= b2.x) && (t2.y >= t1.y && b1.y >= b2.y)) {
        return true;
    }
    else {
        return false;
    }
}

int main() {

    Point top1, top2, bottom1, bottom2;
    cout << "First Top Point: ";
    cin >> top1.x;
    cin >> top1.y;

    cout << endl;

    cout << "First Bottom Point: ";
    cin >> bottom1.x;
    cin >> bottom1.y;

    cout << endl;

    cout << "Second Top Point: ";
    cin >> top2.x;
    cin >> top2.y;

    cout << endl;

    cout << "Second Bottom Point: ";
    cin >> bottom2.x;
    cin >> bottom2.y;

    cout << endl;

    if (isRectangleOverlap(top1, bottom1, top2, bottom2)){
        cout << "Rectangles Overlap" << endl;
    }
    else
    {
        cout << "Rectangles Do Not Overlap" << endl;
    };

    return 0;
}

我希望输出结果如上面的示例中所述。

Answer 1

这里是一种方法。检查矩形可能不重叠的所有条件。为此，以一个矩形作为参考，然后检查另一个矩形是否位于参考矩形的左侧，右侧，顶部或底部。如果没有，它必须重叠。这是代码。

#include <iostream>
#include <vector>
using namespace std;

struct Rectangle {
    int x1;
    int y1;
    int x2;
    int y2;
};

bool isOverlap(Rectangle a, Rectangle b)
{
    bool overlap;

    if (b.y1 >= a.y2)
        overlap = false;
    else if (b.x1 >= a.x2)
        overlap = false;
    else if (a.y1 >= b.y2)
        overlap = false;
    else if (a.x1 >= b.x2)
        overlap = false;
    else 
        overlap = true;

    return overlap;
}

void printPoints(Rectangle &rect)
{
    cout << "Rectangle bottom-left: (" << rect.x1 << ", " << rect.y1 << ")" << endl;
    cout << "Rectangle top-right: (" << rect.x2 << ", " << rect.y2 << ")" << endl;
}

void getInput(Rectangle &rect)
{
    cout << "Enter rectangle. x1: "<< endl;
    cin >> rect.x1;
    cout << "Enter rectangle. y1: "<< endl;
    cin >> rect.y1;
    cout << "Enter rectangle. x2: "<< endl;
    cin >> rect.x2;
    cout << "Enter rectangle. y2: "<< endl;
    cin >> rect.y2;
}

void testRectangleOverlap()
{
    Rectangle a;
    Rectangle b;

    getInput(a);
    getInput(b);

    printPoints(a);
    printPoints(b);

    if (isOverlap(a, b)){
        cout << "Rectangles Overlap" << endl;
    }
    else
    {
        cout << "Rectangles Do Not Overlap" << endl;
    }
}

int main() {

    testRectangleOverlap();

    return 0;
}

在这里您可以使用代码：live code