如何编辑此代码以使其不正确地停止循环？

Question

我是这个网站的新手，它告诉我我的帖子主要是代码。这对我的帖子来说并不重要，它就在这里我可以完成帖子参数。查看输出，如何更改我的代码，以便它不会错误地循环。我已经尝试了一切，但我无法弄清楚如何使它工作。请记住，我是一名初学程序员。我不太懂语法。如何使用最简单的语法使这个循环工作？我不知道为什么它会正确循环，然后在for循环之前显示所有内容，然后在else块中显示所有内容。

#include <iostream>
#include <string>
#include <istream>
#include <stdlib.h>

using namespace std;

int main()
{
    char repeat = 'n';

    string circle;
    string triangle;
    string rectangle;
    string shape;

    long double areaCircle;
    long double areaTriangle;
    long double areaRectangle;
    do
    {   
        cout << "Type the shape you want to find the area for.\n";
        cout << "Circle\n";
        cout << "Triangle\n";
        cout << "Rectangle\n";
        getline(cin,shape);

        if (shape == "circle")
        {
            long double r;
            cout << "Enter the radius of the circle.\n";
            cin >> r;
            areaCircle = (3.14)*(r*r);
            cout << "The area of the circle is " << areaCircle << endl;
            cout << "Enter 'Y' to repeat, 'N' to quit\n";
            cin >> repeat;          
        }
        else if (shape == "triangle")
        {
            long double h, b;
            cout << "Enter the base.\n";
            cin >> b;
            cout << "Enter the height.\n";
            cin >> h;
            areaTriangle = (b*h) / 2;
            cout << "The area of the triangle is " << areaTriangle << endl;
            cout << "Enter 'Y' to repeat, 'N' to quit\n";
            cin >> repeat;
        }
        else if (shape == "rectangle")
        {
            long double l, w;
            cout << "Enter the length.\n";
            cin >> l;
            cout << "Enter the width.\n";
            cin >> w;
            areaRectangle = l * w;
            cout << "The area of the rectangle is " << areaRectangle << endl;
            cout << "Enter 'Y' to repeat, 'N' to quit\n";
            cin >> repeat;
        }
        else if (shape !=circle || shape!= triangle || shape != rectangle)
        {
            cout << shape << "is not a valid shape.\n";
            cout << "Enter 'Y' to repeat, 'N' to quit\n";
            cin >> repeat;
        }
    } 
    while (repeat == 'y');
    system("pause");
    return 0;
}

Click here to see the output of the code