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