將一個方陣旋轉90度

Problem

Rotate a matrix by 90 degrees anti-clockwise

Solution

#include <iostream>

using namespace std;

int** create_matrix(int row, int col)
{
    int **m = new int* [row];
    for(int i = 0; i < row; i++){
        m[i] = new int[col];
    }

    return m;
}

void delete_matrix(int** m, int row)
{
    for(int i = 0; i < row; i ++){
        delete[] m[i];
    }

    delete []m;
}

void print_matrix(int** m, int row, int col)
{
    for(int i = 0; i < row; i ++){
        for(int j = 0; j < col; j++){
            cout << m[i][j] << "  ";
        }
        cout << endl;
    }
}

void initial_matrix(int **m, int row, int col)
{
    for(int i = 0; i < row; i++){
        for(int j = 0; j < col; j ++){
            m[i][j] = rand() % 100;
        }
    }
}

void rotate_matrix(int **m, int size)
{
     for(int level = 0; level < size / 2; level ++){
        for(int i = level; i < size - level - 1; i ++){
            int t = m[level][i];
            m[level][i] = m[i][size - 1 - level];
            m[i][size - 1 - level] = m[size - 1 - level][size - 1 - i];
            m[size - 1 - level][size - 1 - i] = m[size - 1 - i][level];
            m[size - 1 - i][level] = t;
        }
     }
}

int main(int argc, char* argv[])
{
    int size = 6;

    int **m = create_matrix(size, size);
    int i,j;

    initial_matrix(m, size, size);
    cout << "before rotating" << endl;
    print_matrix(m, size, size);

    rotate_matrix(m, size);

    cout << "after rotating" << endl;
    print_matrix(m, size, size);

    return 0;
}

Output

before rotating
41  67  34  0  69  24
78  58  62  64  5  45
81  27  61  91  95  42
27  36  91  4  2  53
92  82  21  16  18  95
47  26  71  38  69  12
after rotating
24  45  42  53  95  12
69  5  95  2  18  69
0  64  91  4  16  38
34  62  61  91  21  71
67  58  27  36  82  26
41  78  81  27  92  47