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c++ - 如何在c ++中修复超出范围的向量下标

问题描述

我正在尝试将“coordinateList”向量的元素与“Buttons”向量的元素进行比较，如果四个不同的 if 语句可以通过它们，则在“countList”向量中增加 1。但是，问题是，每当我为无法通过 if 语句的“coordinateList”输入 2 个数字时，它会在部分上得到“向量下标超出范围”；

if ((coordinateList[j][0] >= Buttons[i][0]) 
    && (coordinateList[j][0] <= Buttons[i][1]) 
    && (coordinateList[j][1] >= Buttons[i][2]) 
    && (coordinateList[j][1] <= Buttons[i][3]))

我不知道如何解决它。

#include <iostream>
#include <vector>

using namespace std;

int main() {

    int numberOfButtons;
    int numberOfClicks;

    cin >> numberOfButtons;

    cin >> numberOfClicks;

    int buttonCoordinate;
    vector <vector<int> > Buttons;

    for (unsigned int i = 0; i < numberOfButtons; i++) {
        vector<int> oneButtonCoordinate;
        for (unsigned int j = 0; j < 4; j++) {
            cin >> buttonCoordinate;
            oneButtonCoordinate.push_back(buttonCoordinate);
        }
        Buttons.push_back(oneButtonCoordinate);
    }



    int XYCoordinate;
    vector <vector<int> > coordinateList;
    vector <int> clickCount;

    for (unsigned int i = 0; i < numberOfClicks; i++) {
        vector<int> oneClickCoordinate;
        for (unsigned int j = 0; j < 2; j++) {
            cin >> XYCoordinate;
            oneClickCoordinate.push_back(XYCoordinate);
        }
        coordinateList.push_back(oneClickCoordinate);
    }


    for (unsigned int i = 0; i < numberOfButtons; i++) {
        clickCount.push_back(0); 
    }

    for (unsigned int j = 0; j < numberOfClicks; j++) {
        for (unsigned int i = Buttons.size() - 1; i >= 0; i--) {
            if ((coordinateList[j][0] >= Buttons[i][0]) && (coordinateList[j][0] <= Buttons[i][1]) && (coordinateList[j][1] >= Buttons[i][2]) && (coordinateList[j][1] <= Buttons[i][3])) {
                clickCount.at(i) += 1;
                break; 
            }
        }
    }


    (skip)


    return 0;
}

正确输入输出示例

输入

2 5

1 5 1 5

3 8 3 8

1 1

3 3

3 5

8 8

3 10

输出

Button: #1: 1

Button: #2: 3

标签： c++vectorsubscript

解决方案

so it is the line 

for (unsigned int i = Buttons.size() - 1; i >= 0; i--)

which ends up in an invalid index (0xFFFFFFFF still >= 0!).

Use instead:

for (int i = (int) Buttons.size() - 1; i >= 0; i--)

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