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| Time Limit: 1000MS | Memory Limit: 65536K | |
| Total Submissions: 1148 | Accepted: 375 | 
Description
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| Figure 1 | Figure 2 | Figure 3a | Figure 3b | Figure 4 | 
Input
Output
Sample Input
4 5 0 2 2 4 4 2 3 2 2 3 4 5 0 2 2 4 4 2 3 2 2 1 7 11 0 3 6 5 3 2 5 7 7 2 4 4 5 3 5 2 4 5 4 0 2 4 0 0
Sample Output
no yes yes
Source
黑白棋的游戏,在n*n的棋盘上,黑棋先手,且最后一步是黑棋。当黑棋从x=0连接的到x=n,时黑棋获胜,问最后一步是不是致胜的一步
每个点都可以和它周围的八个点连接,类似象棋中的马,但是在连接两个点的时候,在连线之间不能有其他的连线(包括黑棋自身的连线)。所以在连接一条线的时候,要判断其他的可能会切割这条线的九条线是否存在。
先判断不包含最后一步的黑棋能不能胜利,再判断加上最后一步后能不能获胜,如果开始不能获胜,后来获胜,那么输出yes,否则,输出no
#include <cstdio>
#include <cstring>
#include <queue>
#include <algorithm>
using namespace std ;
int vis[500] ;
int Map[25][25] , c[500][500] ;//ºÚΪ1£¬°×Ϊ-1
queue <int> que ;
void solve1(int i,int j,int n,int temp)
{
    if( (i-1) >= 0 && (i+1) < n && (j-1) >= 0 && c[ (i-1)*n+j ][ (i+1)*n+(j-1) ] != 0 )
        return ;
    if( (i-1) >= 0 && (j-2) >= 0 && (i+1) < n && (j-1) >= 0 && c[ (i-1)*n+(j-2) ][ (i+1)*n+(j-1) ] != 0 )
        return ;
    if( (j-3) >= 0 && (i+1) < n && (j-1) >= 0 && c[ i*n+(j-3) ][ (i+1)*n+(j-1) ] != 0 )
        return ;
    if( (j-1) >= 0 && (i+1) < n && (j+1) < n && c[ i*n+(j-1) ][ (i+1)*n+(j+1) ] != 0 )
        return ;
    if( (j-1) >= 0 && (i+2) < n && c[ i*n+(j-1) ][ (i+2)*n+j ] != 0 )
        return ;
    if( (j-1) >= 0 && (i+2) < n && (j-2) >= 0 && c[ i*n+(j-1) ][ (i+2)*n+(j-2) ] != 0 )
        return ;
    if( (i-1) >= 0 && (j-1) >= 0 && (i+1) < n && c[ (i-1)*n+(j-1) ][ (i+1)*n+j ] != 0 )
        return ;
    if( (i+1) < n && (j-2) >= 0 && c[ (i+1)*n+j ][ i*n+(j-2) ] != 0 )
        return ;
    if( (j-2) >= 0 && (i+2) < n && (j-1) >= 0 && c[ i*n+(j-2) ][ (i+2)*n+(j-1) ] != 0 )
        return ;
    c[ i*n+j ][ (i+1)*n+(j-2) ] = c[ (i+1)*n+(j-2) ][ i*n+j ] = temp ;
    return ;
}
void solve2(int u,int v,int n,int temp)
{
    if( (u-1) >= 0 && (v-1) >= 0 )
    {
        if( (u+1) < n && c[ (u-1)*n+(v-1) ][ (u+1)*n+v ] != 0 ) return ;
        if( (u+1) < n && (v-2) >= 0 && c[ (u-1)*n+(v-1) ][ (u+1)*n+(v-2) ] != 0 ) return ;
        if( (v-3) >= 0 && c[ (u-1)*n+(v-1) ][ u*n+(v-3) ] != 0 ) return ;
    }
    if( (v-1) >= 0 )
    {
        if( (u-1) >= 0 && (v+1) < n && c[ u*n+(v-1) ][ (u-1)*n+(v+1) ] != 0 ) return ;
        if( (u-2) >= 0 && c[ u*n+(v-1) ][ (u-2)*n+v ] != 0 ) return ;
        if( (u-2) >= 0 && (v-2) >= 0 && c[ u*n+(v-1) ][ (u-2)*n+(v-2) ] != 0 ) return ;
    }
    if( (u+1) < n && (v-1) >= 0 && (u-1) >= 0 && c[ (u+1)*n+(v-1) ][ (u-1)*n+v ] != 0 ) return ;
    if( (u-1) >= 0 && (v-2) >= 0 && c[ (u-1)*n+v ][ u*n+(v-2) ] != 0 ) return ;
    if( (v-2) >= 0 && (u-2) >= 0 && (v-1) >= 0 && c[ u*n+(v-2) ][ (u-2)*n+(v-1) ] != 0 ) return ;
    c[ u*n+v ][ (u-1)*n+(v-2) ] = c[ (u-1)*n+(v-2) ][ u*n+v ] = temp ;
    return ;
}
void solve3(int u,int v,int n,int temp)
{
    if( (u+1) < n )
    {
        if( (u-1) >= 0 && (v-1) >= 0 && c[ (u+1)*n+v ][ (u-1)*n+(v-1) ] != 0 ) return ;
        if( (v-2) >= 0 && c[ (u+1)*n+v ][ u*n+(v-2) ] != 0 ) return ;
        if( (u+2) < n && (v-2) >= 0 && c[ (u+1)*n+v ][ (u+2)*n+(v-2) ] != 0 ) return ;
    }
    if( (u+1) < n && (v-1) >= 0 )
    {
        if( (v+1) < n && c[ (u+1)*n+(v-1) ][ u*n+(v+1) ] != 0 ) return ;
        if( (u+2) < n && (v+1) < n && c[ (u+1)*n+(v-1) ][ (u+2)*n+(v+1) ] != 0 ) return ;
        if( (u+3) < n && c[ (u+1)*n+(v-1) ][ (u+3)*n+v ] != 0 ) return ;
    }
    if( (u+1) < n && (v+1) < n && (v-1) >= 0 && c[ (u+1)*n+(v+1) ][ u*n+(v-1) ] != 0 ) return ;
    if( (v-1) >= 0 && (u+2) < n && c[ u*n+(v-1) ][ (u+2)*n+v ] != 0 ) return ;
    if( (u+2) < n && (u+1) < n && (v-2) >= 0 && c[ (u+2)*n+v ][ (u+1)*n+(v-2) ] != 0 ) return ;
    c[ u*n+v ][ (u+2)*n+(v-1) ] = c[ (u+2)*n+(v-1) ][ u*n+v ] = temp ;
    return ;
}
void solve4(int u,int v,int n,int temp)
{
    if( (u-1) >= 0 )
    {
        if( (u-2) >= 0 && (v-2) >= 0 && c[ (u-1)*n+v ][ (u-2)*n+(v-2) ] != 0 ) return ;
        if( (v-2) >= 0 && c[ (u-1)*n+v ][ u*n+(v-2) ] != 0 ) return ;
        if( (u+1) < n && (v-1) >= 0 && c[ (u-1)*n+v ][ (u+1)*n+(v-1) ] != 0 ) return ;
    }
    if( (u-1) >= 0 && (v-1) >= 0 )
    {
        if( (u-3) >= 0 && c[ (u-1)*n+(v-1) ][ (v-3)*n+v ] != 0 ) return ;
        if( (u-2) >= 0 && (v+1) < n && c[ (u-1)*n+(v-1) ][ (u-2)*n+(v+1) ] != 0 ) return ;
        if( (v+1) < n && c[ (u-1)*n+(v-1) ][ u*n+(v+1) ] != 0 ) return ;
    }
    if( (u-1) >= 0 && (v+1) < n && (v-1) >= 0 && c[ (u-1)*n+(v+1) ][ u*n+(v-1) ] != 0 ) return ;
    if( (v-1) >= 0 && (u-2) >= 0 && c[ u*n+(v-1) ][ (u-2)*n+v ] != 0 ) return ;
    if( (u-2) >= 0 && (v-2) >= 0 && c[ (u-2)*n+v ][ (u-1)*n+(v-2) ] != 0 ) return ;
    c[ u*n+v ][ (u-2)*n+(v-1) ] = c[ (u-2)*n+(v-1) ][ u*n+v ] = temp ;
    return ;
}
int bfs(int u,int n)
{
    int v , i , j ;
    while( !que.empty() ) que.pop() ;
    vis[u] = 1 ;
    que.push(u) ;
    while( !que.empty() )
    {
        u = que.front() ;
        que.pop() ;
        if( u >= (n-1)*n )
            return 1 ;
        for(i = 0 ; i < n*n ; i++)
        {
            if( c[u][i] == 1 && vis[i] == 0 )
            {
                vis[i] = 1 ;
                que.push(i) ;
            }
        }
    }
    return 0 ;
}
void solve(int temp,int n)
{
    int u , v ;
    scanf("%d %d", &u, &v) ;
    Map[u][v] = temp ;
    if( (u+1) < n && (v-2) >= 0 && Map[u][v] == Map[u+1][v-2] )
        solve1(u,v,n,temp);
    if( (u-1) >= 0 && (v+2) < n && Map[u][v] == Map[u-1][v+2] )
        solve1(u-1,v+2,n,temp) ;
    if( (u-1) >= 0 && (v-2) >= 0 && Map[u][v] == Map[u-1][v-2] )
        solve2(u,v,n,temp) ;
    if( (u+1) < n && (v+2) < n && Map[u][v] == Map[u+1][v+2] )
        solve2(u+1,v+2,n,temp) ;
    if( (u+2) < n && (v-1) >= 0 && Map[u][v] == Map[u+2][v-1] )
        solve3(u,v,n,temp) ;
    if( (u-2) >= 0 && (v+1) < n && Map[u][v] == Map[u-2][v+1] )
        solve3(u-2,v+1,n,temp) ;
    if( (u-2) >= 0 && (v-1) >= 0 && Map[u][v] == Map[u-2][v-1] )
        solve4(u,v,n,temp) ;
    if( (u+2) < n && (v+1) < n && Map[u][v] == Map[u+2][v+1] )
        solve4(u+2,v+1,n,temp) ;
}
int main()
{
    int n , m , x , y , u , v , temp , i , j ;
    while( scanf("%d %d", &n, &m) != EOF )
    {
        if( m == 0 && n == 0 ) break ;
        n++ ;
        memset(Map,0,sizeof(vis)) ;
        memset(c,0,sizeof(c)) ;
        temp = 1 ;
        m-- ;
        while( m-- )
        {
            solve(temp,n) ;
            temp = -temp ;
        }
        int k1 = 0 , k2 = 0 ;
        memset(vis,0,sizeof(vis)) ;
        for(j = 0 ; j < n ; j++)
        {
            if(  Map[0][j] == 1 && vis[j] == 0 )
            {
                k1 = bfs(j,n) ;
                if( k1 == 1 ) break ;
            }
        }
        solve(temp,n) ;
        memset(vis,0,sizeof(vis)) ;
        for(j = 0 ; j < n ; j++)
        {
            if(  Map[0][j] == 1 && vis[j] == 0 )
            {
                k2 = bfs(j,n) ;
                if( k2 == 1 ) break ;
            }
        }
        if( k1 == 0 && k2 == 1)
            printf("yes\n") ;
        else
            printf("no\n") ;
    }
    return 0;
}
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原文地址:http://blog.csdn.net/winddreams/article/details/43315469