向量下标超出范围 C++ SFML

Question

我正在尝试制作一个程序，在屏幕上随机生成用户定义的圆圈数（使用 SFML），但是当我选择超过 6 个圆圈时，我得到矢量下标超出范围错误。等于或小于 6 的任何数字都按预期工作。

我已尝试查找错误消息，但我看到的 none 答案适用于我的代码。代码在第一个 for 循环中断，但如果我注释掉第一个循环，它会在第二个循环中断。

这是我的代码：

#include "SFML/Graphics.hpp"
#include <stdlib.h>
#include <iostream>

int main()
{
    srand(time(NULL));

    const int WINDOW_X = 800;
    const int WINDOW_Y = 480;

    sf::RenderWindow window(sf::VideoMode(WINDOW_X, WINDOW_Y), "Epidemic Simulation", sf::Style::Close | sf::Style::Titlebar);

    int numPeople = 10;
    float size = 5;
    int status = 0;

    std::vector<sf::CircleShape> person(size);

    for (int i = 0; i < numPeople; ++i)
    {
        if (status == 0)
            person[i].setFillColor(sf::Color::Green);
        else if (status == 1)
            person[i].setFillColor(sf::Color::Red);
        else if (status == 2)
            person[i].setFillColor(sf::Color::Black);
        else
        {
            std::cout << ("Error: Incorrect color value");
            person[i].setFillColor(sf::Color::Green);
        }
        person[i].setFillColor(sf::Color::Green);
    }

    for (int i = 0; i < numPeople; ++i)
    {
        int xPos = rand() % WINDOW_X - (size * 2);
        int yPos = rand() % WINDOW_Y - (size * 2);

        if (xPos < (size * 2))
            xPos = 0;

        if (yPos < (size * 2))
            yPos = 0;

        std::cout << ("X position: ") << xPos << (", Y position: ") << yPos << "\n";

        person[i].setPosition(xPos, yPos);
        person[i].setRadius(size);
    }

    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }

        window.clear(sf::Color::White);

        for (int i = 0; i < numPeople; ++i)
            window.draw(person[i]);

        window.display();
    }

    return 0;
}

Answer 1

因为你用 size = 5 启动了 person(size) 并且循环上升到 numPeople = 10。你可能想写：

std::vector<sf::CircleShape> person(numPeople);

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