vc++数组问题 代码

Question

1.定义4×5的二维数组，实现其转置
2.定义4×5的二维数组，求出最大值，最小值和平均值
3.实现两个二维数组相乘

Answer 1

1.矩阵转置

#include <iostream>
using namespace std;
int main()
{
    int a[4][5], i, j;
    int b[5][4];
    //输入二维数组
    for (i = 0; i < 4; i++)
    {
        for (j = 0; j < 5; j++)
            cin >> a[i][j];
    }
    //转置
    for (i = 0; i < 5; i++)
    {
        for (j = 0; j < 4; j++)
        {
            b[i][j] = a[j][i];
        }
    }
    //输出二维数组
    for (i = 0; i < 5; i++)
    {
        for (j = 0; j < 4; j++)
        {
            if(j<3)
                cout << b[i][j] << " ";
            else
                cout << b[i][j] << endl;
        }
            
        
    }
    return 0;
}

2.最大值、最小值、平均值：

#include <iostream>
using namespace std;
int main()
{
    int a[4][5], i, j;
    int max, min;
    float ave = 0; //平均值
    //输入二维数组
    for (i = 0; i < 4; i++)
    {
        for (j = 0; j < 5; j++)
        {
            cin >> a[i][j];
            ave += a[i][j];
            if (i == 0 && j == 0)
            {
                max = min = a[0][0];
            }
            else
            {
                if (a[i][j] > max) max = a[i][j];
                if (a[i][j] < min) min = a[i][j];
            }
        }
            
    }
    cout << "max=" << max << ",min=" << min << ",avg=" << ave/20 << endl;
    return 0;
}

3.二维数组相乘

#include <iostream>
using namespace std;
int main()
{
    int** a, ** b, ** c, i, j, k;
    int m, n;
    cout << "请输入二维数组a的行数和列数：";
    cin >> m >> n;
    cout << "请输入" << m << "*" << n << "的二维数组a：" << endl;
    a = new int* [m];
    for (i = 0; i < m; i++)
    {
        a[i] = new int[n];
        for (j = 0; j < n; j++)
            cin >> a[i][j];
    }
    cout << "请输入" << n << "*" << m << "的二维数组b：" << endl;
    b = new int* [n];
    for (i = 0; i < n; i++)
    {
        b[i] = new int[m];
        for (j = 0; j < m; j++)
            cin >> b[i][j];
    }

    c = new int* [m];
    for (i = 0; i < m; i++)
    {
        c[i] = new int[m];
        for (j = 0; j < m; j++)
        {
            c[i][j] = 0;
            //行列相乘
            for (k = 0; k < n; k++)
                c[i][j] += a[i][k] * b[k][j];
        }
    }
    //输出
    for (i = 0; i < m; i++)
    {
        for (j = 0; j < m; j++)
        {
            if (j < m - 1)
                cout << c[i][j] << " ";
            else
                cout << c[i][j] << endl;
        }
    }
    return 0;
}