View Code of Problem 3311

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
using namespace std;
string num="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
int vist[4][2]={{0,1},{1,0},{0,-1},{-1,-0}};
int book[100][100]={0};
char mapp[100][100];    int d,n,m;   int cnt=1;
void dfs(int x,int y,int asd)
{
    if(x<0||y<0||x>=n||y>=m)
        return;

            int tx=x+vist[asd%4][0];
            int ty=y+vist[asd%4][1];
            if(tx<0||ty<0||tx>=n||ty>=m||book[tx][ty])
                {//tx=x+vist[d%4][0];ty=y+vist[d%4][1];
                  return;
                }
            else {
                book[tx][ty]=1;
                mapp[tx][ty]=num[cnt%26];
                //cout<<
                cnt++;
                dfs(tx,ty,asd);
            }
            dfs(tx,ty,asd+1);
}
int main()
{

    while(cin>>n>>m)
    {
        int x=0,y=0;
        memset(book,0,sizeof(book));
        mapp[0][0]='A';
        book[0][0]=1;
        d=0;
        cnt=1;
        dfs(0,0,0);
        for(int i=0;i<n;i++)
        {
            for(int j=0;j<m-1;j++)
                cout<<"   "<<mapp[i][j];
            cout<<"   "<<mapp[i][m-1]<<endl;
        }
    }
    return 0;
}