BNUOJ 2345 Muddy Fields

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <climits>
 7 #include <vector>
 8 #include <queue>
 9 #include <cstdlib>
10 #include <string>
11 #include <set>
12 #define LL long long
13 #define INF 0x3f3f3f3f
14 using namespace std;
15 char mp[60][60];
16 int row,col;
17 int r[60][60],c[60][60];
18 vector<int>g[6000];
19 int lik[6000],cnt;
20 bool used[6000];
21 void init(){
22     int i,j;
23     char pre = ‘-‘;
24     cnt = 1;
25     memset(r,0,sizeof(r));
26     memset(c,0,sizeof(c));
27     for(i = 0; i < row; i++){
28         for(j = 0; j < col; ){
29             if(mp[i][j] == ‘*‘){
30                 while(j < col && mp[i][j] == ‘*‘) {r[i][j] = cnt;j++;}
31                 cnt++;
32             }else j++;
33         }
34     }
35     for(i = 0; i < col; i++){
36         for(j = 0; j < row; ){
37             if(mp[j][i] == ‘*‘){
38                 while(j < row && mp[j][i] == ‘*‘){c[j][i] = cnt;j++;}
39                 cnt++;
40             }else j++;
41         }
42     }
43 }
44 bool dfs(int u){
45     for(int i = 0; i < g[u].size(); i++){
46         if(!used[g[u][i]]){
47             used[g[u][i]] = true;
48             if(lik[g[u][i]] == -1 || dfs(lik[g[u][i]])){
49                 lik[g[u][i]] = u;
50                 return true;
51             }
52         }
53     }
54     return false;
55 }
56 int main(){
57     int i,j,ans;
58     while(~scanf("%d%d",&row,&col)){
59         for(i = 0; i < row; i++)
60             scanf("%s",mp[i]);
61         for(i = 0; i < 6000; i++){
62             g[i].clear();
63             lik[i] = -1;
64         }
65         init();
66         for(i = 0; i < row; i++){
67             for(j = 0; j < col; j++){
68                 if(mp[i][j] == ‘*‘){
69                     g[r[i][j]].push_back(c[i][j]);
70                     g[c[i][j]].push_back(r[i][j]);
71                 }
72             }
73         }
74         for(ans = 0,i = 1; i < cnt; i++){
75             memset(used,false,sizeof(used));
76             if(dfs(i)) ans++;
77         }
78         cout<<(ans>>1)<<endl;
79     }
80     return 0;
81 }