poj 1185

上一题的升级版 

dp[i][j][k] 表示第 i 行状态为 k 第i-1行状态为 j

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <sstream>
#include <string>
#include <cstring>
#include <algorithm>
#include <iostream>
#define maxn 2005
#define INF 0x3f3f3f3f
#define inf 10000000
#define MOD 100000000
#define ULL unsigned long long
#define LL long long

using namespace std;

char g[110][15];
int dp[105][70][70], mapp[110], sta[70], cc[70];
int n, m, num;

bool if_ok(int x) {
    if(x & (x<<1)) return false;
    if(x & (x<<2)) return false;
    return true;
}

int countone(int x) {
    int ans = 0;
    while(x) {
        ++ ans;
        x = x&(x-1);
    }
    return ans;
}

void init() {
    memset(dp, -1, sizeof(dp));
    memset(mapp, 0, sizeof(mapp));
    num = 0;
    for(int i = 0; i < (1<<m); ++ i) {
        if(if_ok(i)) sta[num++] = i;
    }
    // printf("num : %d\n", num);
}

int main()
{
    while(scanf("%d%d", &n, &m) == 2) {
        init();
        // printf("ff: %d\n", num);
        for(int i = 0; i < n; ++ i) {
            scanf("%s", g[i]);
        }
        for(int i = 0; i < n; ++ i) {
            for(int j = 0; j < m; ++ j) {
                if(g[i][j] == 'H') mapp[i] = mapp[i] | (1<<j);
            }
        }
        for(int i = 0; i < num; ++ i) {
            cc[i] = countone(sta[i]);
            if((mapp[0] & sta[i]) == 0) {
                dp[0][0][i] = cc[i];
            }
        }
        for(int i = 0; i < num; ++ i) {
            if(mapp[1] & sta[i]) continue;
            for(int j = 0; j < num; ++ j) {
                if(sta[j]&sta[i]) continue;
                if(dp[0][0][j] == -1) continue;
                dp[1][j][i] = max(dp[1][j][i], dp[0][0][j]+cc[i]);
            }
        }
        for(int i = 2; i < n; ++ i) {
            for(int j = 0; j < num; ++ j) {
                if(mapp[i] & sta[j]) continue;
                for(int k = 0; k < num; ++ k) {
                    if(sta[k] & sta[j]) continue;
                    for(int q = 0; q < num; ++ q) {
                        if(sta[q] & sta[k] || sta[q] & sta[j]) continue;
                        if(dp[i-1][k][q] == -1) continue;
                        dp[i][q][j] = max(dp[i][q][j], dp[i-1][k][q]+cc[j]);
                    }
                }
            }
        }
        int ans = 0;
        for(int i = 0; i < n; ++ i) {
            for(int j = 0; j < num; ++ j) {
                for(int k = 0; k < num; ++ k) {
                    ans = max(ans, dp[i][j][k]);
                }
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}