c++ - 将列添加到二维数组

Question

用户输入任何所需的array，代码查找每一列，如果任何列中的任何元素等于数字y。那么代码应该添加一个新的零列在它前面。

Code

#include <pch.h>
#include <iostream>

using namespace std;

int main()
{
int y, rows, columns;
std::cout << "Enter the number of rows: ";
std::cin >> rows;
std::cout << "Enter the number of columns: ";
std::cin >> columns;
std::cout << "Enter a number Y: ";
std::cin >> y;

//-----------------------Generating 2-D array---------------------------------------------------------
int **array = new int*[2 * rows];
for (int i = 0; i < rows; i++)
    array[i] = new int[columns];
//------------------------Generating bool--------------------------------------------------------------
bool *arrx = new bool[columns];
//-----------------------Input Array Elements---------------------------------------------------------
std::cout << "Enter the elements" << std::endl;
for (int i = 0; i < columns; i++)
    for (int j = 0; j < rows; j++)
        std::cin >> array[i][j];
//--------------------Loop for the array output--------------------------------------------------------
for (int i = 0; i < columns; i++) {
    for (int j = 0; j < rows; j++) {
        std::cout << array[i][j] << " ";
    }
    std::cout << "\n";
}
//-------------------Loop for finding columns with even numbers----------------------------------------
for (int i = 0; i < columns; i++) {
    arrx[i] = false;
    for (int j = 0; j < rows; j++) {
        if (array[j][i] == y) {
            arrx[i] = true;
        }
    }
}
std::cout << "\n";
//--------------------Loop for addition of new columns infront of even numbers--------------------------
for (int i = 0; i < columns; i++) {
    for (int j = 0; j < rows; j++) {
        std::cout << array[i][j] << " ";
    }
    std::cout << "\n";
    if (arrx[i]) {
        for (int i = 0; i < rows; i++) {
            std::cout << 0 << " ";
        }
        std::cout << "\n";
    }
}

return 0;
}

这里的代码只向 array 添加行，而我需要添加 columns 。我曾尝试将 array[i][j] 更改为 array[j][i] 但徒劳无功。

Answer 1

你需要更换

for (int i = 0; i < columns; i++) {
    for (int j = 0; j < rows; j++) {
        std::cout << array[i][j] << " ";
    }
    std::cout << "\n";
    if (arrx[i]) {
        for (int i = 0; i < rows; i++) {
            std::cout << 0 << " ";
        }
        std::cout << "\n";
    }
}

与

for (int i = 0; i < rows; i++) {
    for (int j = 0; j < columns; j++) {
        std::cout << array[i][j] << " ";
        if (arrx[j]) {
           std::cout << 0 << " ";
         }
    }
}

这会在列值被标记的每个元素后打印一个零。您试图做的是逐列打印到标准输出，这不是它的工作方式。

此外，我敦促您考虑使用 std::vector 而不是普通指针，以避免像此处那样您忘记释放内存的错误。