hdu 4274 2012长春赛区网络赛 树形dp ***

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 #include<map>
 8 using namespace std;
 9 #define MOD 1000000007
10 const int INF=1000010;
11 const double eps=1e-5;
12 typedef long long ll;
13 #define cl(a) memset(a,0,sizeof(a))
14 #define ts printf("*****\n");
15 const int N=10005;
16 int n,m,tt,tot=0,head[N],dp[N];
17 int maxw;
18 bool flag;
19 struct edge
20 {
21     int to,next;
22 }edge[N*2];
23 int up[N],low[N];
24 void addedge(int a,int b)
25 {
26     edge[tot].to=a;
27     edge[tot].next=head[b];
28     head[b]=tot++;
29 }
30 void init()
31 {
32     memset(head,-1,sizeof(head));
33     tot=0;
34 }
35 void dfs(int u,int pre)
36 {
37     if(flag)    return;
38     if(up[u]!=-1&&low[u]>up[u])
39     {
40         flag=1;
41         return;
42     }
43     int le=0;
44     int sum=0;
45     for(int i=head[u];i!=-1;i=edge[i].next)
46     {
47         int v=edge[i].to;
48         if(v==pre)  continue;
49         le=1;
50         dfs(v,u);
51         sum+=low[v];
52     }
53     if(!le)   return;
54     low[u]=max(sum+1,low[u]);
55     if(up[u]!=-1&&low[u]>up[u])
56     {
57         flag=1;
58         return;
59     }
60 }
61 int main()
62 {
63     int i,j,k;
64     #ifndef ONLINE_JUDGE
65     freopen("1.in","r",stdin);
66     #endif
67     while(scanf("%d",&n)!=EOF)
68     {
69         init();
70         for(i=2;i<=n;i++)
71         {
72             int u;
73             scanf("%d",&u);
74             addedge(i,u);
75             addedge(u,i);
76         }
77         for(i=1;i<=n;i++)    up[i]=-1,low[i]=1;
78         scanf("%d",&m);
79         for(i=0;i<m;i++)
80         {
81             int u,v,w;
82             char c[10];
83             scanf("%d%s%d",&u,c,&w);
84             if(c[0]==‘<‘)  up[u]=w-1;
85             else if(c[0]==‘>‘)  low[u]=w+1;
86             else low[u]=up[u]=w;
87         }
88         flag=0;
89         dfs(1,-1);
90         if(flag)
91         {
92             printf("Lie\n");
93         }
94         else    printf("True\n");
95     }
96 }