Hdu 3804 树链剖分 第5遍

标签：io   os   ar   for   数据   sp   on   amp   ad   

不能原谅自己的错误。。还怀疑人家的数据错了，瞬间感觉自己弱爆了

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<iostream>
#include<cstring>
#include<algorithm>
#define lson id << 1
#define rson id << 1|1
#include<cstdio>
using namespace std;
const int M = 100008;
int father[M],dep[M],top[M],siz[M],ti[M],son[M];
int idx,tp = 0;
const int inf = 0x3ffff;
struct line_tree{
    int l,r,Max,Min,mark;
    int mid(){
        return (l+r)/2;
    }
}node[M*4];
struct {
    int head;
}H[M];
struct{
    int v,next;
}E[M*4];
void add(int u,int v){
    E[tp].v =  v;
    E[tp].next = H[u].head;
    H[u].head = tp++;
}
void init(){
    memset(E,-1,sizeof(E));
    memset(H,-1,sizeof(H));
    tp = 0;idx = 0;
}
void dfs_1(int u,int fa){
    son[u] = 0;siz[u] = 1;dep[u] = dep[fa] + 1; father[u] = fa;
    for(int i=H[u].head;i!=-1;i=E[i].next){
        int v = E[i].v;
        if(v == fa)continue;
        dfs_1(v,u);
        siz[u] += siz[v];
        if(siz[v] > siz[son[u]]) son[u] = v;
    }
}

void dfs_2(int u,int fa){
    top[u] = fa;
    ti[u] = idx++;
    if(son[u])dfs_2(son[u],fa);
    for(int i=H[u].head;i!=-1;i=E[i].next){
        int v = E[i].v;
        if(v == father[u]||v == son[u])continue;
        dfs_2(v,v);
    }
}
/* 线段树*/

void  build_tree(int id,int l,int r){
    node[id].l = l;node[id].r = r;
    node[id].Max  = -1;
    if(l == r)return;
    int mid = node[id].mid();
    build_tree(lson,l,mid);
    build_tree(rson,mid+1,r);
}

void push_up(int id){
    node[id].Max = max(node[lson].Max,node[rson].Max);
}
void  update(int id,int k,int w){

    if(node[id].l == k&&node[id].r == k){
       node[id].Max = w;
       return;
    }
    int mid = node[id].mid();
    if(k <= mid)update(lson,k,w);
    else update(rson,k,w);
    push_up(id);
}
int query(int id,int l,int r){
    if( node[id].l == l&&node[id].r == r)return node[id].Max;
    int mid= node[id].mid();
    if(r <=mid)return query(lson,l,r);
    else if(l > mid)return query(rson,l,r);
    else return max( query(lson,l,mid),query(rson,mid+1,r));
    push_up(id);
}
int findMax(int u,int v){
    int f1 = top[u];
    int f2 = top[v];
    int mmax = -1;
    while(f1 !=f2){
        if(dep[f1] < dep[f2]){
            swap(f1,f2);
            swap(u,v);
        }
        mmax = max(mmax,query(1,ti[f1],ti[u]));
        u = father[f1];f1 = top[u];
    }

    if(u == v)return mmax;
    if(dep[u] > dep[v])swap(u,v);
    mmax =  max(mmax,query(1,ti[son[u]],ti[v]));
    return mmax;
}
struct Node{
    int x,y,val;
}e[M];
struct xx{
    int x,y,i,d;
}h[M];
bool cmp(xx a,xx b){
    return a.y < b.y;
}
bool cmp1(Node a,Node b){
    return a.val < b.val;
}
bool cmp2(xx a,xx b){
    return a.i < b.i;
}
int main(){
    //freopen("input.txt","r",stdin);
    int n,m;
    int T;
    scanf("%d",&T);
    while(T--){
        init();
        scanf("%d",&n);
        for(int i=0;i<n-1;i++){
            scanf("%d%d%d",&e[i].x,&e[i].y,&e[i].val);
            add(e[i].x,e[i].y);
            add(e[i].y,e[i].x);
        }
        dfs_1(1,1);
        dfs_2(1,1);
        build_tree(1,1,idx-1);
        scanf("%d",&m);
        for(int i=0;i<m;i++){
            scanf("%d%d",&h[i].x,&h[i].y);
            h[i].i = i;
        }
         sort(e,e+n-1,cmp1);
         sort(h,h+m,cmp);
         int  t = 0,x = 0;;
         while(t < m){
            while(h[t].y >= e[x].val &&x < n-1 ){
                if(dep[e[x].x] > dep[e[x].y])
                    swap(e[x].x,e[x].y);
                    update(1,ti[e[x].y],e[x].val);
                    x++;
            }
            h[t].d = findMax(h[t].x,1);
            t++;
         }
        sort(h,h+m,cmp2);
        for(int i=0;i<m;i++){
            printf("%d\n",h[i].d);
        }

    }

}

疑人家的数据错了。。瞬间感觉自己简直弱爆了

Hdu 3804 树链剖分 第5遍

标签：io   os   ar   for   数据   sp   on   amp   ad   

原文地址：http://blog.csdn.net/wyl_zheyang/article/details/39935421