#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    int M[100][100]={0};
    int x,y;
    int tot=M[x=0][y=0]=1;
    int n,m;
    cin>>n>>m;
    while(tot<n*m)
    {
        while(y+1<m&&!M[x][y+1]) M[x][y=y+1]=++tot;
        while(x+1<n&&!M[x+1][y]) M[x=x+1][y]=++tot;
        while(y-1>=0&&!M[x][y-1]) M[x][y=y-1]=++tot;
        while(x-1>=0&&!M[x-1][y]) M[x=x-1][y]=++tot;
    }
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            cout<<M[i][j]<<" ";
        }
        cout<<endl;
    }
    return 0;
}

蛇形矩阵是基础,一定要掌握.