Question

我是编程（一般）和C ++（特别是）的新手。我正在使用数组并尝试执行以下操作：

1) create a 12x 12 array of (pseudo) random numbers
2) add a 13th row that sums up the columns
3) add a 13th column that sums up the rows
4) add a number to the diagonal of the matrix (e.g. 1 in [R1][C1], 2 in [R2][C2], etc)
5) output the adjusted matrix in step 4

我基本上能够'破解'（尽管绝对不是最优雅的方式）。对于上面的＃2和＃3，我使用12x12阵列，然后只输出两个SEPARATE数组。

是否可以创建一个包含总和行和列的13x13矩阵？可以使用指针来简化这个吗？

如果是这样，有人会指出我正确的方向（我没有与他们合作的经验）？

以下是代码：

#include "stdafx.h"
#include <iostream>
#include <cstdlib>
#include <iomanip>

using namespace std;

const int N = 12;
const int M = 12;

int Matrix_M[N][M] = {0};
int rowSum[N] = {0};
int colSum[M] = {0};

void generateArray();
void Parity();
void Average();
void addError();

int main()
{
    generateArray();
    Parity();
    addError();
    Parity();

    return 0;
}

void generateArray()
{

    // generates the column headers (months of the year)

    cout << endl << endl;
    cout << left << setw(5) << "Jan"
        << left << setw(5) << "Feb"
        << left << setw(5) << "Mar"
        << left << setw(5) << "Apr"
        << left << setw(5) << "May"
        << left << setw(5) << "Jun"
        << left << setw(5) << "Jul"
        << left << setw(5) << "Aug"
        << left << setw(5) << "Sep"
        << left << setw(5) << "Oct"
        << left << setw(5) << "Nov"
        << left << setw(5) << "Dec" << endl;

    cout << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---" << endl;

    // sets the seed for the number generator
    unsigned setSeed = 1023;
    srand(setSeed);

    // generates the matrix using pseudo-random numbers

    // fill the rows first
    for (int i = 0; i < N; i++)
    {

        // the fill the columns
        for (int j = 0; j < M; j++)
        {
            Matrix_M[i][j] = rand() % 100;

            // outputs the raw matrix
            cout << left << setw(4) << Matrix_M[i][j] << " ";
        }
        cout << endl;
    }
    cout << endl << endl;
}

void Parity()
{

    cout << "The parity values are:" << endl << endl;

    // generates the column headers (months of the year)

    cout << endl << endl;
    cout << left << setw(5) << "Jan"
        << left << setw(5) << "Feb"
        << left << setw(5) << "Mar"
        << left << setw(5) << "Apr"
        << left << setw(5) << "May"
        << left << setw(5) << "Jun"
        << left << setw(5) << "Jul"
        << left << setw(5) << "Aug"
        << left << setw(5) << "Sep"
        << left << setw(5) << "Oct"
        << left << setw(5) << "Nov"
        << left << setw(5) << "Dec" << endl;

    cout << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---" << endl;

    cout << left << setw(12) << "Columns" << left << setw(12) << "Rows" << endl;
    cout << left << setw(12) << "-------" << left << setw(12) << "----" << endl;

    // sums the row and column elements

    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < M; ++j)
        {
            rowSum[i] += Matrix_M[i][j];
            colSum[i] += Matrix_M[j][i];
        }

        // outputs the sums
        cout <<  setw(5) << colSum[i];
        cout << left << setw(65) << rowSum[i] << endl;
    }
}


void addError()
{
    // some explanatory text
    cout << endl << endl << endl;
    cout << "The following matrix introduces an error along the diagonal" << endl;

    // generates the column headers (months of the year)

    cout << endl << endl;
    cout << left << setw(5) << "Jan"
        << left << setw(5) << "Feb"
        << left << setw(5) << "Mar"
        << left << setw(5) << "Apr"
        << left << setw(5) << "May"
        << left << setw(5) << "Jun"
        << left << setw(5) << "Jul"
        << left << setw(5) << "Aug"
        << left << setw(5) << "Sep"
        << left << setw(5) << "Oct"
        << left << setw(5) << "Nov"
        << left << setw(5) << "Dec" << endl;

    cout << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---"
        << left << setw(5) << "---" << endl;

    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < M; j++)
        {

            // introduces an error to the previously-generated number in the original matrix
            // adds 1 to [R1][C1], adds 2 to [R2][C2], adds 3 to [R1][C1] ... adds 12 to [R12][C12]
            if (i == j)
            {
                Matrix_M[i][j] += (i+1)*1;
            }

            // outputs the matrix containing errors 
            cout << left << setw(4) << Matrix_M[i][j] << " ";
        }
        cout << endl;
    }
    cout << endl << endl;
}

提前致谢， -Ryan

Answer 1

通常，数组的使用在 C ++ 中被弃用。例如，使用std::vector代替：

const int N = 12;
const int M = 12;

std::vector<int> matrix = std::vector<int>((N+1)*(M+1),0);    //creating the matrix adding one extra row and column for the sums;

//filling the matrix
for(int ii=0; ii<N; ii++)
{
    for(int jj=0; jj<M; jj++)
    {
        matrix[ii*(M+1) + jj] = rand() % 100;
        matrix[ii*(M+1) + M] += matrix[ii*(M+1) + jj];    //updating the sum;
    }
}

这会计算所有行的总和，因此您可以引入一个额外的循环来计算列的总和。

如何“绑定”对现有矩阵的列和行求和的数组？

1 个答案: