poj 2488

标签：des   style   http   color   os   strong   io   width   

Description

Background 
The knight is getting bored of seeing the same black and white squares again and again and has decided to make a journey 
around the world. Whenever a knight moves, it is two squares in one direction and one square perpendicular to this. The world of a knight is the chessboard he is living on. Our knight lives on a chessboard that has a smaller area than a regular 8 * 8 board, but it is still rectangular. Can you help this adventurous knight to make travel plans? 

Problem 
Find a path such that the knight visits every square once. The knight can start and end on any square of the board.

Input

Output

Sample Input

3
1 1
2 3
4 3

Sample Output

Scenario #1:
A1

Scenario #2:
impossible

Scenario #3:
A1B3C1A2B4C2A3B1C3A4B2C4

Source

TUD Programming Contest 2005, Darmstadt, Germany

AC代码：

#include<iostream>
#include<cstring>
using namespace std;
int p,q;
int G[30][30];
int sucess;
char ch[1000];
int a[8][2]={{-1,-2},{1,-2},{-2,-1},{2,-1},{-2,1},{2,1},{-1,2},{1,2}};
int dfs(int x,int y,int step){
    if(x<0 || x>p-1 || y<0 || y>q-1 || G[x][y]) return 0;
    G[x][y]=1;
    if(step==p*q){
        ch[2*step]='\0';
        return 1;
    }
    for(int k=0;k<8;k++){
        if(dfs(x+a[k][0],y+a[k][1],step+1)){
            ch[2*(step+1)-2]=y+a[k][1]+'A';
            ch[2*(step+1)-1]=x+a[k][0]+'1';
            return 1;
        }
    }
    G[x][y]=0;
    return 0;
}
int main(){
    int T; cin>>T;
    for(int cas=1;cas<=T;cas++){
        cin>>p>>q;
        for(int j=0;j<q;j++){
            for(int i=0;i<p;i++){
                sucess=0;
                memset(G,0,sizeof(G));
                ch[0]=j+'A';
                ch[1]=i+'1';
                if(dfs(i,j,1)){
                    sucess=1;
                    break;
                }
            }
            if(sucess)
                break;
        }
        cout<<"Scenario #"<<cas<<":"<<endl;
        if(!sucess)
            cout<<"impossible"<<endl<<endl;
        else
            cout<<ch<<endl<<endl;
    }
    return 0;
}

poj 2488,布布扣,bubuko.com

poj 2488

标签：des   style   http   color   os   strong   io   width   

原文地址：http://blog.csdn.net/my_acm/article/details/38095513