輸入一個(gè)矩陣，按照從外向里以順時(shí)針的順序依次打印出每一個(gè)數(shù)字，例如，如果輸入如下矩陣：
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
則依次打印出數(shù)字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.

#include <iostream>
#include<stdio.h>
using namespace std;

int main()
{
    int m,n,count;
    //cin>>m>>n;
    while(cin>>m>>n){     //多個(gè)測試樣例，要用while循環(huán)，這里出錯(cuò)多次
    int a[m][n];
    count=m*n;
    for (int i=0; i<m; i++)
    {
        for (int j=0; j<n; j++)
        {
            cin>>a[i][j];
        }
    }

    int num=0,i=0,j=0;
     while (num<count)
     {
        while (j<n&&a[i][j]!=-1)
        {
            cout<<a[i][j]<<" ";
            a[i][j]=-1;
            j++;
            num++;
            //cout<<"j"<<j;
            //cout<<"A\n";
        }
        j--;
        i++;    //最終發(fā)現(xiàn)這里錯(cuò)了
        //cout<<"j"<<j;
        //cout<<"B\n";
        while(i<m&&a[i][j]!=-1)//短路所以后面不會(huì)越界
        {
            cout<<a[i][j]<<" ";
            a[i][j]=-1;
            i++;
            num++;
            //cout<<"C\n";
        }
        i--;
        j--;
        //cout<<"j"<<j;
        while (j>-1&&a[i][j]!=-1)
        {
            cout<<a[i][j]<<" ";
            a[i][j]=-1;
            j--;
            num++;
        }
        j++;
        i--;
        while (i>-1&&a[i][j]!=-1)
        {
            cout<<a[i][j]<<" ";
            a[i][j]=-1;
            i--;
            num++;
        }
        i++;
        j++;
     }
    printf("\n");
    }
    return 0;
}

注意事項(xiàng)

1.循環(huán)開始結(jié)束的重要節(jié)點(diǎn)，邊界條件

2. 九度垃圾，多個(gè)測試樣例要用while輸入，單個(gè)一直報(bào)錯(cuò)還不告訴錯(cuò)在哪里，莫名其妙