Algorithm --> 顺序打印矩阵

顺序打印矩阵

思路

参考代码

#include <iostream>
using namespace std;
void printNumAsClockwise(int a[][], int row, int col)
{
    if (row <  || col < )
        return;
    int up = , down = row -, left = , right = col -;
    int i = ;
    while(up <= down && left <= right)
    {
        for(i = left; i <= right; ++i)
            cout << a[up][i] << " ";
        ++up;

        for(i = up; i <= down; ++i)
            cout << a[i][right] << " ";
        --right;

        for(i = right; i >= left; --i)
            cout << a[down][i] << " ";
        --down;

        for(i = down; i >= up; --i)
            cout << a[i][left] << " ";
        ++left;

    }
    cout << endl;
}

int main()
{
    int a[][] = {{,,,}, {,,,}, {,,,}, {,,,}};
    cout << sizeof(a) / sizeof(int) << endl;
    printNumAsClockwise(a, , );
};

二维数组可以用一维来代替

#include <iostream>
using namespace std;
void printNumAsClockwise(int *a, int row, int col)
{
    if (row <  || col < )
        return;
    int up = , down = row -, left = , right = col -;
    int i = ;
    while(up <= down && left <= right)
    {
        for(i = left; i <= right; ++i)
            cout << a[up * col + i] << " ";
        ++up;

        for(i = up; i <= down; ++i)
            cout << a[i * col + right] << " ";
        --right;

        for(i = right; i >= left; --i)
            cout << a[down * col + i] << " ";
        --down;

        for(i = down; i >= up; --i)
            cout << a[i * col + left] << " ";
        ++left;

    }
    cout << endl;
}

int main()
{
    int a[][] = {{,,,}, {,,,}, {,,,}, {,,,}};
    cout << sizeof(a) / sizeof(int) << endl;
    printNumAsClockwise((int*)a, , );
};

注意

注意判别参数符合范围

if (row <  || col < )
        return;

结果