bzoj1468 Tree

  1 #include<algorithm>
  2 #include<iostream>
  3 #include<cstdlib>
  4 #include<cstring>
  5 #include<cstdio>
  6 #include<string>
  7 #include<cmath>
  8 #include<ctime>
  9 #include<queue>
 10 #include<stack>
 11 #include<map>
 12 #include<set>
 13 #define rre(i,r,l) for(int i=(r);i>=(l);i--)
 14 #define re(i,l,r) for(int i=(l);i<=(r);i++)
 15 #define Clear(a,b) memset(a,b,sizeof(a))
 16 #define inout(x) printf("%d",(x))
 17 #define douin(x) scanf("%lf",&x)
 18 #define strin(x) scanf("%s",(x))
 19 #define LLin(x) scanf("%lld",&x)
 20 #define op operator
 21 #define CSC main
 22 typedef unsigned long long ULL;
 23 typedef const int cint;
 24 typedef long long LL;
 25 using namespace std;
 26 void inin(int &ret)
 27 {
 28     ret=0;int f=0;char ch=getchar();
 29     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=1;ch=getchar();}
 30     while(ch>=‘0‘&&ch<=‘9‘)ret*=10,ret+=ch-‘0‘,ch=getchar();
 31     ret=f?-ret:ret;
 32 }
 33 struct treap
 34 {
 35     int ed,root;
 36     int ch[40040][2],w[40040],c[40040],s[40040],r[40040];
 37     void inin(){ed=root=0;}
 38     void maintain(int k){if(k)s[k]=c[k]+s[ch[k][0]]+s[ch[k][1]];}
 39     void rotate(int &k,int d){int p=ch[k][d^1];ch[k][d^1]=ch[p][d];ch[p][d]=k;maintain(k);maintain(p),k=p;}
 40     void add(int &k,int x)
 41     {
 42         if(!k){k=++ed,w[k]=x,c[k]=s[k]=1,r[k]=rand(),ch[k][0]=ch[k][1]=0;return ;}
 43         s[k]++;
 44         if(w[k]==x){c[k]++;return ;}
 45         int d=x>w[k];
 46         add(ch[k][d],x);
 47         if(r[ch[k][d]]<r[k])rotate(k,d^1);
 48     }
 49     int query(int k,int x)
 50     {
 51         if(!k)return 0;
 52         if(w[k]==x)return s[ch[k][0]];
 53         if(w[k]>x)return query(ch[k][0],x);
 54         return s[ch[k][0]]+c[k]+query(ch[k][1],x);
 55     }
 56 }t;
 57 int n,head[40040],next[80080],zhi[80080],w[80080],ans,ed,k,sum,root;
 58 void add(int a,int b,int c)
 59 {
 60     next[++ed]=head[a],head[a]=ed,zhi[ed]=b,w[ed]=c;
 61     next[++ed]=head[b],head[b]=ed,zhi[ed]=a,w[ed]=c;
 62 }
 63 bool bo[40040];
 64 int f[40040],s[40040],temp[40040],dis[40040];
 65 void getroot(int x,int fa)
 66 {
 67     f[x]=0;s[x]=1;
 68     for(int i=head[x];i;i=next[i])if(zhi[i]!=fa&&!bo[zhi[i]])
 69     {
 70         getroot(zhi[i],x);
 71         s[x]+=s[zhi[i]];
 72         f[x]=max(f[x],s[zhi[i]]);
 73     }
 74     f[x]=max(f[x],sum-s[x]);
 75     if(f[x]<f[root])root=x;
 76 }
 77 void dfs(int x,int fa)
 78 {
 79     temp[++temp[0]]=dis[x];
 80     for(int i=head[x];i;i=next[i])if(!bo[zhi[i]]&&zhi[i]!=fa)
 81     {
 82         dis[zhi[i]]=dis[x]+w[i];
 83         dfs(zhi[i],x);
 84     }
 85 }
 86 void js(int x)
 87 {
 88     bo[x]=1;t.inin();
 89     for(int i=head[x];i;i=next[i])if(!bo[zhi[i]])
 90     {
 91         dis[zhi[i]]=w[i];
 92         dfs(zhi[i],x);
 93         re(j,1,temp[0])
 94         {
 95             if(temp[j]<=k)ans++;
 96             ans+=t.query(t.root,k-temp[j]+1);
 97         }
 98         re(j,1,temp[0])t.add(t.root,temp[j]);
 99         temp[0]=0;
100     }
101     for(int i=head[x];i;i=next[i])if(!bo[zhi[i]])
102     {
103         root=0;sum=s[zhi[i]];
104         getroot(zhi[i],x);
105         js(root);
106     }
107 }
108 int CSC()
109 {
110     inin(n);sum=n;
111     re(i,1,n-1)
112     {
113         int q,w,e;
114         inin(q),inin(w),inin(e);
115         add(q,w,e);
116     }
117     inin(k);
118     f[0]=n+1;
119     getroot(1,0);
120     js(root);
121     printf("%d",ans);
122     return 0;
123 }