有关数据范围

 1 #include<cstdio>
 2 #include<cstring>
 3 #define INF 2147483000
 4 using namespace std;
 5 int n,m,S,T;
 6 struct ss{
 7     int next,to,w,cp;
 8 }x[100410];
 9 int first[4010],num;
10 int dep[4010];
11 int que[200000];
12 char s[1010];
13 void bui_(int ,int ,int );
14 void build(int ,int ,int );
15 int bfs();
16 int dfs(int ,int );
17 int main()
18 {
19     freopen("splay.in","r",stdin);
20     freopen("splay.out","w",stdout);
21     int i,j,k,ans=0,add;
22     scanf("%d%d",&n,&m);
23     S=0,T=3*n+1;
24     scanf("%s",s+1);
25     for(i=1;i<=n;i++){
26         if(s[i]==‘J‘)
27             bui_(S,i,1);
28         if(s[i]==‘T‘)
29             bui_(i,T,1);
30         bui_(i,i+n,1);
31         bui_(i+n,i+2*n,1);
32     }
33     for(i=1;i<=m;i++){
34         scanf("%d%d",&j,&k);
35         if(s[j]==‘J‘&&(s[k]==‘J‘||s[k]==‘E‘))
36             bui_(j,k+n,1);
37         if(s[j]==‘J‘&&s[k]==‘T‘)
38             bui_(2*n+j,k,1);
39         if(s[j]==‘E‘&&s[k]==‘T‘)
40             bui_(2*n+j,k,1);
41         if(s[k]==‘J‘&&(s[j]==‘J‘||s[j]==‘E‘))
42             bui_(k,j+n,1);
43         if(s[k]==‘J‘&&s[j]==‘T‘)
44             bui_(2*n+k,j,1);
45         if(s[k]==‘E‘&&s[j]==‘T‘)
46             bui_(2*n+k,j,1);
47     }
48     while(bfs())
49         while(add=dfs(S,INF))
50             ans+=add;
51     printf("%d",ans);
52     return 0;
53 }
54 void bui_(int f,int t,int d){
55     build(f,t,d);x[num].cp=num+1;
56     build(t,f,0);x[num].cp=num-1;
57 }
58 void build(int f,int t,int d){
59     x[++num].next=first[f];
60     x[num].to=t;
61     x[num].w=d;
62     first[f]=num;
63 }
64 int bfs(){
65     memset(dep,0,sizeof(dep));
66     int h=0,t=1,j;
67     que[t]=S;
68     while(h<t){
69         ++h;
70         for(j=first[que[h]];j;j=x[j].next)
71             if(x[j].w&&x[j].to!=S&&!dep[x[j].to]){
72                 dep[x[j].to]=dep[que[h]]+1;
73                 que[++t]=x[j].to;
74             }
75     }
76     if(dep[T])return 1;
77     return 0;
78 }
79 int dfs(int now,int min){
80     int j,re=0;
81     if(now==T)
82         return min;
83     for(j=first[now];j;j=x[j].next)
84     {
85         if(x[j].w&&dep[x[j].to]==dep[now]+1){
86             re=dfs(x[j].to,min<x[j].w?min:x[j].w);
87             if(re){
88                 x[j].w-=re;
89                 x[x[j].cp].w+=re;
90                 return re;
91             }
92             dep[x[j].to]=0;
93         } 
94     }
95     return re;
96 }