poj 2488

简单dfs

#include <stdio.h>
#include <stdlib.h>
int n,m,time,ture;
int a[9][9];
int make(int t,int s)
{
    if(ture) return(0);
    if(t>=1&&t<=n&&s>=1&&s<=m&&a[t][s]==0)
    {
        a[t][s]=++time;
        if(time==n*m)
        {
            ture=1;
            int i,j,k;
            for(k=1;k<=n*m;k++)
            for(i=1;i<=n;i++)
            for(j=1;j<=m;j++)
            if(a[i][j]==k)
            printf("%c%d",j+'A'-1,i);
            printf("\n");
            return(0);
        }
        search(t,s);
        time--;
        a[t][s]=0;
    }
}
int search(int t,int s)
{
    if(ture) return(0);
    make(t-1,s-2);
    make(t+1,s-2);
    make(t-2,s-1);
    make(t+2,s-1);
    make(t-2,s+1);
    make(t+2,s+1);
    make(t-1,s+2);
    make(t+1,s+2);
}
int main()
{
    int i,j,k,p;
    scanf("%d",&k);
    for(p=1;p<=k;p++)
    {
        scanf("%d %d",&n,&m);
        printf("Scenario #%d:\n",p);
        for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
        a[i][j]=0;
        time=1;
        ture=0;
        a[1][1]=1;
        if(n*m==1) {printf("A1\n");ture=1;}
        else search(1,1);
        if(!ture) printf("impossible\n");
        printf("\n");
    }
    return 0;
}