HDOJ4366解题报告

  1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstdlib>
  4 #include <cmath>
  5 #include <vector>
  6 #include <ctime>
  7 #include <map>
  8 #include <stack>
  9 #include <queue>
 10 #include <cstring>
 11 #include <algorithm>
 12 using namespace std;
 13 
 14 #define sacnf scanf
 15 #define scnaf scanf
 16 #define maxn  50010
 17 #define maxm 26
 18 #define inf 1061109567
 19 #define Eps 0.00001
 20 const double PI=acos(-1.0);
 21 #define mod 7
 22 #define MAXNUM 10000
 23 void Swap(int &a,int &b) {int t=a;a=b;b=t;}
 24 int Abs(int x) {return (x<0)?-x:x;}
 25 typedef long long ll;
 26 typedef unsigned int uint;
 27 
 28 struct node
 29 {
 30     int pos,abi,loy;
 31     bool operator < (const node &a) const
 32     {
 33         if(abi==a.abi) return loy>a.loy;
 34         return abi>a.abi;
 35     }
 36 } a[maxn];
 37 
 38 struct node1
 39 {
 40     int pos,val;
 41 } q[maxn];
 42 
 43 vector<int> G[maxn];
 44 int tme;
 45 int st[maxn],ed[maxn];
 46 int tabi[maxn],tloy[maxn];
 47 int ans[maxn];
 48 int tree[maxn*4];          ///loy最大的点的编号
 49 
 50 bool cmp(node1 a,node1 b)
 51 {
 52     return tabi[a.val]>tabi[b.val];
 53 }
 54 
 55 void dfs(int u,int fa)
 56 {
 57     st[u]=++tme;
 58     int len=G[u].size();
 59     for(int i=0;i<len;i++)
 60     {
 61         int v=G[u][i];
 62         if(v!=fa) dfs(v,u);
 63     }
 64     ed[u]=tme;
 65 }
 66 
 67 void build_tree(int l,int r,int dir)
 68 {
 69     if(l==r)
 70     {
 71         tree[dir]=1;
 72         return;
 73     }
 74     int m=(l+r)>>1;
 75     build_tree(l,m,dir<<1);
 76     build_tree(m+1,r,dir<<1|1);
 77     tree[dir]=1;
 78 }
 79 
 80 void add(int l,int r,int dir,int pos,int val)
 81 {
 82     if(l==r)
 83     {
 84         tree[dir]=(tloy[tree[dir]]<tloy[val])?val:tree[dir];
 85         return;
 86     }
 87     int m=(l+r)>>1;
 88     if(pos<=m) add(l,m,dir*2,pos,val);
 89     else add(m+1,r,dir*2+1,pos,val);
 90     tree[dir]=(tloy[tree[dir*2]]<tloy[tree[dir*2+1]])?tree[dir*2+1]:tree[dir*2];
 91 }
 92 
 93 int query(int l,int r,int dir,int ql,int qr)
 94 {
 95     if(ql>qr) return 1;
 96     if(ql>r||l>qr) return 1;
 97     if(ql<=l&&r<=qr) return tree[dir];
 98     int m=(l+r)>>1,t1,t2;
 99     t1=query(l,m,dir<<1,ql,qr);
100     t2=query(m+1,r,dir<<1|1,ql,qr);
101     return (tloy[t1]<tloy[t2])?t2:t1;
102 }
103 
104 int main()
105 {
106     //freopen("data.in","r",stdin);
107     //freopen("data.out","w",stdout);
108     //clock_t st=clock();
109     int n,m,T;scanf("%d",&T);tree[0]=-1;
110     while(T--)
111     {
112         sacnf("%d%d",&n,&m);
113         int x;
114 
115         a[1].pos=1;a[1].abi=a[1].loy=-1;
116         tloy[1]=tabi[1]=-1;
117         for(int i=1;i<=n;i++) G[i].clear();
118 
119         for(int i=2;i<=n;i++)
120         {
121             scanf("%d%d%d",&x,&a[i].loy,&a[i].abi);
122             x++;a[i].pos=i;tabi[i]=a[i].abi;tloy[i]=a[i].loy;
123             G[x].push_back(i);G[i].push_back(x);
124         }
125 
126         tme=0;
127         dfs(1,-1);
128         build_tree(1,n,1);
129 
130         sort(a+1,a+1+n);       ///按ability降序排列    a-->第i个人的数据
131 
132         for(int i=1;i<=m;i++)                  ///q-->第i个询问的序号及询问编号
133         {
134             scanf("%d",&q[i].val);q[i].val++;
135             q[i].pos=i;
136         }
137         sort(q+1,q+1+m,cmp);          ///按ability降序排列
138 
139         int i=1,j=1;
140         while(i<=m)
141         {
142             int p=a[j].pos;
143             if(a[j].abi<=tabi[q[i].val])
144             {
145                 int temp=query(1,n,1,st[q[i].val]+1,ed[q[i].val]);
146                 ans[q[i].pos]=temp-1;i++;
147                 if(i>m) break;
148             }
149             else if(j<n)
150             {
151                 add(1,n,1,st[p],p);j++;
152             }
153         }
154         for(i=1;i<=m;i++) printf("%d\n",(ans[i]==0)?-1:ans[i]);
155     }
156     //clock_t ed=clock();
157     //printf("\n\nTime Used : %.5lf Ms.\n",(double)(ed-st)/CLOCKS_PER_SEC);
158     return 0;
159 }