C/C++实现矩阵各种运算

我会带着你远行 2022-04-03 15:58 220阅读 0赞

## 程序很简单，重要的是二维指针的动态分配内存 ##

type **Matrix ;//row为行,col为列
        Matrix=(type **) malloc(row*sizeof(type *)) ;
        for(int i=0; i<row; i++)
            Matrix[i] = (type *)malloc(col * sizeof(type ));

类似数组a\[2\]\[3\]，他一共两行，每一行有3个元素，所以为他先分配两行内存，然后每一行再分配3列内存

Matrix类型是type\*\*，先为它分配row行内存，内存类型与Matrix一样  
Matrix=(type\*\*) malloc(row*sizeof(type*))  
每一行分配col列内存，内存类型与Matix\[i\]一样，也就是type\*  
Matrix\[i\] = (type\*)malloc(col \* sizeof(type ));

其中一个功能的结果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0NjM3OTQ_size_16_color_FFFFFF_t_70]

## 下面是完整代码 ##

#include <iostream>
    #include <malloc.h>
    #include <stdio.h>
    using namespace std;
    
    typedef struct
    {
        //结构体
        int row,col;
        //二维指针，目的是动态分配内存
        float **matrix;
    } Matrix;
    
    typedef struct
    {
        char *name;
        char *number;
    } Student;
    
    Matrix CreateMatrix()
    {
        Matrix m;
        int row,col;
        cout << "输入行数与列数：" << endl;
        cin >> row >> col;
        float **enterMatrix ;
        enterMatrix=(float**) malloc(row*sizeof(float*)) ;
        for(int i=0; i<row; i++)
            enterMatrix[i] = (float *)malloc(col * sizeof(float));
        cout<<"输入你的矩阵："<<endl;
        for(int i=0; i<row; i++)
        {
            for(int j=0; j<col; j++)
            {
                cin >> enterMatrix[i][j];
            }
        }
        m.col = col;
        m.row = row;
        m.matrix = enterMatrix;
        return m;
    }
    
    //初始化一个行为row列为col矩阵
    Matrix InitMatrix(int row,int col)
    {
        Matrix m;
        float **matrix ;
        matrix=(float**) malloc(row*sizeof(float*)) ;
        for(int i=0; i<row; i++)
            matrix[i] = (float *)malloc(col * sizeof(float));
        for(int i=0; i<row; i++)
        {
            for(int j=0; j<col; j++)
            {
                matrix[i][j] = 0;
            }
        }
        m.col = col;
        m.row = row;
        m.matrix = matrix;
        return m;
    }
    
    Matrix add(Matrix m1, Matrix m2)
    {
        for(int i=0; i<m1.row; i++)
        {
            for(int j=0; j<m1.col; j++)
            {
                m1.matrix[i][j] = m1.matrix[i][j] +m2.matrix[i][j];
            }
        }
        return m1;
    }
    
    Matrix sub(Matrix m1, Matrix m2)
    {
        for(int i=0; i<m1.row; i++)
        {
            for(int j=0; j<m1.col; j++)
            {
                m1.matrix[i][j] = m1.matrix[i][j] -m2.matrix[i][j];
            }
        }
        return m1;
    }
    
    int calRowCol(Matrix M1,Matrix M2,int row,int col)//row为M1的行 col为m2的列
    {
        int result = 0;
        int same = M1.col;
        for(int j=0; j<same; j++)
        {
            result+=M1.matrix[row][j]*M2.matrix[j][col];
        }
    
        return result;
    }
    
    
    Matrix Mul(Matrix m1, Matrix m2)
    {
        Matrix result = InitMatrix(m1.row,m2.col);
        for(int i=0; i<m1.row; i++)
        {
            for(int j=0; j<m2.col; j++)
            {
                result.matrix[i][j] = calRowCol(m1,m2,i,j);
            }
        }
        return result;
    }
    
    Matrix numMul(Matrix m, int num)
    {
        cout<<"数值:"<<num<<endl;
        for(int i=0; i<m.row; i++)
        {
            for(int j=0; j<m.col; j++)
            {
                m.matrix[i][j] = m.matrix[i][j]*num;
            }
        }
        return m;
    }
    
    Matrix printMatrix(Matrix m)
    {
        for(int i=0; i<m.row; i++)
        {
            for(int j=0; j<m.col; j++)
            {
                cout << m.matrix[i][j] << "  ";
            }
            cout<<endl;
        }
    }
    
    int main()
    {
        int num = 0;
        do
        {
            cout<<"*************************************\n";
            cout<<"*              菜单                 *\n";
            cout<<"*          1.矩阵相加               *\n";
            cout<<"*          2.矩阵相减               *\n";
            cout<<"*          3.矩阵相乘               *\n";
            cout<<"*          4.矩阵数乘               *\n";
            cout<<"*          5.退出                   *\n";
            cout<<"*************************************\n";
            cin>>num;
            if(1 == num|| 2 == num || 3 == num)
            {
                cout<<"请输入矩阵1"<<endl;
                Matrix m1 = CreateMatrix();
                cout<<"请输入矩阵2"<<endl;
                Matrix m2 = CreateMatrix();
                cout<<"两矩阵为"<<endl;
                printMatrix(m1);
                cout<<endl;
                printMatrix(m2);
                switch(num)
                {
                case 1:
                {
                    if(m1.col!=m2.col || m1.row!=m2.row)
                    {
                        cout<<"行列不同"<<endl;
                    }
                    else{
                        cout<<"结果为："<<endl;
                        printMatrix(add(m1,m2));
                    }
                    break;
                }
                case 2:
                {
    
                    if(m1.col!=m2.col || m1.row!=m2.row)
                    {
                        cout<<"参数错误"<<endl;
                    }
                    else{
                        cout<<"结果为："<<endl;
                        printMatrix(sub(m1,m2));
                    }
                    break;
    
                }
                case 3:
                {
                    if(m1.col!=m2.row)
                    {
                        cout<<"参数错误"<<endl;
                    }
                    else{
                        cout<<"结果为："<<endl;
                        printMatrix(Mul(m1,m2));
                    }
                    break;
                }
                default:
                    break;
                }
            }
            else if(4 == num)
            {
                int number = 1;
                cout<<"请输入矩阵"<<endl;
                Matrix m = CreateMatrix();
                cout<<"请输入数值"<<endl;
                cin>>number;
                cout<<"矩阵为："<<endl;
                printMatrix(m);
                cout<<"数值为："<<endl;
                cout<<number<<endl;
                printMatrix(numMul(m,number));
            }
            cout<<"按回车继续....";
    
            getchar();
            getchar();
            system("cls");
        }
        while(1 == num|| 2 == num || 3 == num ||4 == num);
        return 0;
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTE0NjM3OTQ_size_16_color_FFFFFF_t_70]: /images/20220403/3239d031a8cb467baf917526a2d4d895.png