Submission #535358

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Source Code Expand

#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define all(c) c.begin(),c.end()
#define pb push_back
#define fs first
#define sc second
#define show(x) cout << #x << " = " << x << endl
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
using namespace std;

const int MAX_V=100000,LOGV=17,inf=1e9+7;
int N,Q,a[MAX_V];
int par[MAX_V][LOGV],depth[MAX_V],mx[MAX_V][LOGV];
vector<int> G[MAX_V];
void dfs(int v,int p){
	if(p<0) depth[v]=0;
	else depth[v]=depth[p]+1;
	par[v][0]=p;
	mx[v][0]=a[v];
	for(int u:G[v]){
		if(u!=p) dfs(u,v);
	}
}
void genlca(){
	dfs(0,-1);
	for(int i=1;i<LOGV;i++){
		rep(v,N){
			if(par[v][i-1]==-1)	par[v][i]=-1,mx[v][i]=inf;
			else{
				par[v][i]=par[par[v][i-1]][i-1];
				mx[v][i]=min(mx[v][i-1],mx[par[v][i-1]][i-1]);
			}
		}
	}
}
int lca(int u,int v){
	if(depth[u]<depth[v]){
		swap(u,v);
	}
	int d=depth[u]-depth[v];
	rep(i,LOGV){
		if((d>>i)&1) u=par[u][i];
	}
	if(u==v) return u;
	for(int i=LOGV-1;i>=0;i--){
		if(par[u][i]!=par[v][i]){
			u=par[u][i];
			v=par[v][i];
		}
	}
	return par[v][0];
}
void up(int &u,int to,int& x){
	for(int i=LOGV-1;i>=0;i--){
		if(depth[u]-(1<<i)<depth[to]) continue;
		if(mx[u][i]>x) u=par[u][i];
	}
	x%=a[u];
	if(u!=to) u=par[u][0];
	x%=a[u];
}
int downto(int u,int v,int d){
//	u->v down dist d
	int dist=depth[v]-depth[u];
	if(dist<d) return -1;
	int D=dist-d;
	rep(i,LOGV) if((D>>i)&1) v=par[v][i];
	return v;
}
void down(int &u,int to,int& x){
	for(int i=LOGV-1;i>=0;i--){
		int w=downto(u,to,(1<<i));
		if(w==-1) continue;
		if(mx[w][i]>x) u=w;
//		printf("nxtu=%d\n",u);
	}
	x%=a[u];
	if(u!=to) u=downto(u,to,1);
	x%=a[u];
}
int main(){
	cin>>N>>Q;
	rep(i,N) cin>>a[i];
	rep(i,N-1){
		int x,y;
		cin>>x>>y;
		x--,y--;
		G[x].pb(y);
		G[y].pb(x);
	}
	genlca();
	rep(tt,Q){
		int x,u,v;
		cin>>x>>u>>v;
		u--,v--;
		int L=lca(u,v);
//		show(L);
		while(u!=L){
			up(u,L,x);
		}
		x%=a[L];
		while(u!=v){
//			show(u);
			down(u,v,x);
		}
//			show(u);
		x%=a[v];
		cout<<x<<endl;
	}
}

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