zoukankan      html  css  js  c++  java
  • poj2243BFS

    Knight Moves
    Time Limit: 1000MS   Memory Limit: 65536K
    Total Submissions: 14114   Accepted: 7870

    Description

    A friend of you is doing research on the Traveling Knight Problem (TKP) where you are to find the shortest closed tour of knight moves that visits each square of a given set of n squares on a chessboard exactly once. He thinks that the most difficult part of the problem is determining the smallest number of knight moves between two given squares and that, once you have accomplished this, finding the tour would be easy. 
    Of course you know that it is vice versa. So you offer him to write a program that solves the "difficult" part. 

    Your job is to write a program that takes two squares a and b as input and then determines the number of knight moves on a shortest route from a to b.

    Input

    The input will contain one or more test cases. Each test case consists of one line containing two squares separated by one space. A square is a string consisting of a letter (a-h) representing the column and a digit (1-8) representing the row on the chessboard.

    Output

    For each test case, print one line saying "To get from xx to yy takes n knight moves.".

    Sample Input

    e2 e4
    a1 b2
    b2 c3
    a1 h8
    a1 h7
    h8 a1
    b1 c3
    f6 f6
    

    Sample Output

    To get from e2 to e4 takes 2 knight moves.
    To get from a1 to b2 takes 4 knight moves.
    To get from b2 to c3 takes 2 knight moves.
    To get from a1 to h8 takes 6 knight moves.
    To get from a1 to h7 takes 5 knight moves.
    To get from h8 to a1 takes 6 knight moves.
    To get from b1 to c3 takes 1 knight moves.
    To get from f6 to f6 takes 0 knight moves.
    #include<iostream>
    #include<cstdio>
    #include<queue>
    #include<cstring>
    using namespace std;
    struct node
    {
        int x;
        int y;
        int step;
    }q,end,w;
    int vis[10][10];
    char x,y;
    int a,b;
    int u[][2]={-2,-1,-1,-2,1,-2,2,-1,2,1,1,2,-1,2,-2,1};
    int sum,c,d;
    queue<node>s;
    void bfs(int x,int y)
    {
        end.x=d;
        end.y=c;
        q.x=x;
        q.y=y;
        q.step=0;
        queue<node>s;
        while(!s.empty())s.pop();
        s.push(q);
        while(!s.empty())
        {
            q=s.front();
            s.pop();
            if(q.x==end.x&&q.y==end.y)
            {
                printf("To get from %c%d to %c%d takes %d knight moves.
    ",a-1+'a',b,c-1+'a',d,q.step);
                return;
            }
            for(int i=0;i<8;i++)
            {
                w.x=q.x+u[i][0];
                w.y=q.y+u[i][1];
                w.step=q.step+1;
                if(w.x>0&&w.x<9&&w.y>0&&w.y<9&&vis[w.x][w.y]==0)
                {
                    s.push(w);
                    vis[w.x][w.y]=1;
                }
            }
        }
    }
    int main()
    {
        while(cin>>x>>b>>y>>d)
        {
            memset(vis,0,sizeof(vis));
            a=x-'a'+1;
            c=y-'a'+1;
            bfs(b,a);
        }
    }
  • 相关阅读:
    一个在LINUX里安装MS LIB的工具
    Debian 5网易更新源
    ZT:apache转发实现iis和apache共享80端口
    SuSE 安装 永中Office
    [ZT]用dd备份主引导记录
    opensuse 11.3使用fcitx的办法
    在debian5上安装vmware server 2.0.2的尝试
    VHCS wait to be added问题解决
    debian里的NAT转发设置
    Linux操作系统下安装USB移动硬盘的方法
  • 原文地址:https://www.cnblogs.com/--lr/p/7073676.html
Copyright © 2011-2022 走看看