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来源：互联网发布：知止可以不殆什么意思编辑：程序博客网时间：2024/06/08 02:53
////  main.cpp//  639////  Created by Fangpin on 15/3/9.//  Copyright (c) 2015年 FangPin. All rights reserved.//#include <iostream>#include <cstring>#include <cstdio>#include <string>using namespace std;int map[7][7];int ans,n;void dfs(int x,int y,int sum){    if(!map[x][y]){        ++y;        if(y==n+1) {y=1;++x;}        if(x<=n)            dfs(x,y,sum);    }    else{        int c1=0,c2=0,i=x,j=y;        while(map[i][j]){            if(map[i][j]==2) ++c1;            ++i;        }        i=x;j=y;        while(map[i][j]){            if(map[i][j]==2) ++c1;            --i;        }        i=x;j=y;        while(map[i][j]){            if(map[i][j]==2) ++c2;            ++j;        }        i=x;j=y;        while(map[i][j]){            if(map[i][j]==2) ++c2;            --j;        }        if(c1 || c2){            ++y;            if(y==n+1) {y=1;++x;}            if(x<=n)                dfs(x,y,sum);        }        else{            ++sum;            ans=max(ans,sum);            int i=x,j=y;            ++y;            if(y==n+1) {y=1;++x;}            if(x<=n){                map[i][j]=2;                dfs(x,y,sum);                --sum;                map[i][j]=1;                dfs(x,y,sum);            }        }    }}int main(int argc, const char * argv[]) {    // insert code here...    while(scanf("%d",&n),n){        memset(map,0,sizeof(map));        string s;        for(int i=1;i<=n;++i){            cin>>s;            for(int j=0;j<s.size();++j){                if(s[j]=='.')                    map[i][j+1]=1;                else map[i][j+1]=0;            }        }        ans=0;        dfs(1,1,0);        printf("%d\n",ans);    }    return 0;}
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