Question

我试图将真值表复制到2D矢量中。第一个数字是表的输入数，所以我接受第一行，然后我开始填充向量。这是来自sample.txt的真值表：

这是我的代码：

#include <iostream>
#include <fstream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <math.h>
#include <vector>
#include <fstream>
using namespace std;

string getFileName();
string userFile;
fstream file;
int width;
vector < vector <int> >newArray; // 2d array as a vector of vectors

int main() {
    vector < vector <int> >array; // 2d array as a vector of vectors
    int row = 0; // Row counter
    int col = 0;
    int count = 0;
    int add = 0;
    userFile = getFileName();
    // Read file
    file.open(userFile.c_str(), ios::in); // Open file

    if (file.is_open()) { // If file has correctly opened...

        // Output debug message
        cout << "File correctly opened" << endl;
        string nLine;
        string line;
        getline(file, nLine);
        width = atoi(nLine.c_str());
        cout << "Width: " << width << endl;


        // Dynamically store data into array
        while (getline(file, nLine)) { // ... and while there are no errors,
            vector <int> rowVector(width-1); // vector to add into 'array' (represents a row)
            array.push_back(rowVector); // add a new row,

            cout << "row" << row <<": ";
            col = 0;
            for(std::string::size_type i = 0; i < nLine.size(); ++i) { //iterate string
                if(nLine[i] == '1'){
                    array[row][col] = 1;
                    cout << " Col " << col << ": " << array[row][col];
                    col++;
                }
                else if(nLine[i] == '0'){
                    array[row][col] = 0;
                    cout << " Col " << col << ": " << array[row][col];
                    col++;
                }
                else{ //skip spaces

                }           
            }
            cout << endl;
            row++; // Keep track of actual row 
        }
    }
    else cout << "Unable to open file" << endl;
    file.close();

    cout << "Copied" << endl;
    for(int i = 0; i < row; i++){
        for(int j = 0; j <= width; j++){
            cout << array[i][j] << " ";
        }
        cout << endl;
    }
    //erase lines that have output of 0
    // for(int i = 0; i < row; i++){
    //  if(array[i][width] == 0){
    //      cout << i << " " << array[i][width]<< endl;
    //      array.erase(array.begin() + i);
    //      count++;
    //  }
    // }
    row -= count;
    cout << "New rows: " << row << endl;





    return 0;
}

string getFileName(){
    cout << "Enter file name pls: " << endl;
    cin >> userFile;

    file.open(userFile.c_str(), ios::in); // Open file
    if (file.is_open()) { // If file has correctly opened...
        cout << "File correctly opened" << endl;
    }
    else {
        cout << "Unable to open file" << endl;
        getFileName();
    }
    file.close();
    return userFile;
}

以下是执行的截图：

output Screenshot

当我将它们放入向量时输出它们时，行和列似乎都是正确的，但是当我回去时，前8行左右是完全错误的，其余的都是正确的...我是不知道为什么。我在if（file.is_open（））语句之后关闭文件（第67行）后立即打印它。

感谢您的帮助，一切顺利

Answer 1

在这一行

vector <int> rowVector(width-1); // vector to add into 'array' (represents a row)

您声明rowVector的大小为width-1，在此测试用例中，您的width为4，因此rowVector的大小为3.但是您的测试case包含5列0或1。因此，您尝试访问显示未定义行为的超出范围索引。

要解决此问题，请将rowVector大小等于width+1

vector <int> rowVector(width+1); // vector to add into 'array' (represents a row)

将facttable加载到2d向量中

1 个答案: