#include<stdio.h>int a[105][105];int c=1,n,t=0;void dfs(int x,int y){    if(x<1||y<1||x>n||y>n){        t++;        return;    }    if(a[x][y]!=0){        t++;        return;    }    a[x][y]=c;    c++;    while(c<=n*n){    if(t%4==0) dfs(x+1,y);    else if(t%4==1) dfs(x,y-1);    else if(t%4==2) dfs(x-1,y);  //遍历思路    else dfs(x,y+1);    }}int main(){    int i,j;    scanf("%d",&n);    dfs(1,n);    for(i=1;i<=n;i++){        for(j=1;j<=n;j++){            if(j==1) printf("%d",a[i][j]);            else printf(" %d",a[i][j]);        }        printf("\n");    }    return 0;} /**************************************************************    Problem: 1541    User: 2016207228    Language: C    Result: 正确    Time:1 ms    Memory:1312 kb****************************************************************/