POJ 3254 状态压缩

题目链接  http://poj.org/problem?id=3254

开始改变 自己写状态压缩的方式了  以前的那种写法 完全自创,很复杂一样;换了大牛的思路,,,不用 DFS 了 

#include<iostream>
#include<stdio.h>
#include<cstring>
#include<algorithm>
#define mod 100000000
using namespace std;

int N,M,ans,map[13],cnt[(1<<13)],dp[13][(1<<13)];
void inint( )
{
    ans = 0;
    for( int i = 0; i < (1<<M); i++ )
        if( !(i&(i<<1)) )cnt[ans++] = i;
}
int main( )
{
    int i,j,k,val;
    while( scanf("%d%d",&N,&M) != EOF)
    {
        memset( map,0,sizeof(map) );
        memset( dp, 0,sizeof(dp)  );
        for( i = 1; i <= N; i++ )
        for( j = 1; j <= M; j++ )
        {
            scanf("%d",&val);
            if( !val )map[i] |= ( 1<<(j-1) );
        }
        inint( );
        for( i = 0; i < ans; i++ )
        if( !(map[1]&cnt[i]) )
               dp[1][i] = 1;
        for( i = 2; i <= N; i++ )
        for( j = 0; j <ans; j++ )
        {
            if( map[i-1]&cnt[j] )continue;
            for( k = 0; k < ans; k++ )
            {
                if( (cnt[k]&map[i]) || (cnt[k]&cnt[j]) )continue;
                dp[i][k] = (dp[i][k]+dp[i-1][j])%mod;
            }
        }
        int res = 0;
        for( i = 0; i < ans; i++ )
        res = (res + dp[N][i])%mod;
        printf("%d\n",res);
    }
    return 0;
}

  

原文地址:https://www.cnblogs.com/wulangzhou/p/3061404.html