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
时间: 2024-10-12 12:21:43