Code:

#include<cstdio>
#include<algorithm>
#include<string>
#include<iostream>
#include<cstring>
using namespace std;
void setIO(string a){
	freopen((a+".in").c_str(),"r",stdin);
}
const int maxn=200000;
const int mod=201314;
int n,q;
int dep[maxn],top[maxn],son[maxn],A[maxn],fa[maxn];
struct Get_Tree{
	int cnt,cnt2;
	int nex[maxn],to[maxn],head[maxn],siz[maxn];
	void add_edge(int u,int v){
		nex[++cnt]=head[u];
		head[u]=cnt;
		to[cnt]=v;
	}
	void dfs1(int u,int depth){
		dep[u]=depth;
		siz[u]=1;
		for(int v=head[u];v;v=nex[v]){
			dfs1(to[v],depth+1);
			siz[u]+=siz[to[v]];
			if(!son[u]||siz[to[v]]>siz[son[u]]) son[u]=to[v];
		}
	}
	void dfs2(int u,int tp){
        top[u]=tp;
        A[u]=++cnt2;
        if(son[u])dfs2(son[u],tp);
        for(int v=head[u];v;v=nex[v])
            if(to[v]!=son[u])dfs2(to[v],to[v]);
    }
    void solve(){
    	dfs1(1,1);
    	dfs2(1,1);
    }
}tree;
struct Segment_Tree{
	#define lson (o<<1)
	#define rson (o<<1)|1
	int sumv[maxn<<2],lazy[maxn<<2];
	void pushdown(int l,int r,int o){
		if(lazy[o]){
			int mid=(l+r)>>1;
			sumv[lson]+=(mid-l+1)*lazy[o];
			sumv[rson]+=(r-mid)*lazy[o];
			lazy[lson]+=lazy[o];
			lazy[rson]+=lazy[o];
			sumv[lson]%=mod;
			sumv[rson]%=mod;
			lazy[lson]%=mod;
			lazy[rson]%=mod;
			lazy[o]=0;
		}
	}
	void pushup(int o){
		sumv[o]=sumv[lson]+sumv[rson];
	}
	void update(int l,int r,int L,int R,int k,int o){
		if(l>r||l>R||r<L)return;
		if(l>=L && r<=R){
			sumv[o]+=(r-l+1)*k;
			lazy[o]+=k;
			sumv[o]%=mod;
			lazy[o]%=mod;
			return;
		}
		int mid=(l+r)>>1;
		pushdown(l,r,o);
		update(l,mid,L,R,k,lson);
		update(mid+1,r,L,R,k,rson);
		pushup(o);
	}
	int query(int l,int r,int L,int R,int o){
		if(l>r||l>R||r<L)return 0;
		if(l>=L&&r<=R) return sumv[o];
		int mid=(l+r)>>1;
		pushdown(l,r,o);
		return (long long)(query(l,mid,L,R,lson)+query(mid+1,r,L,R,rson))%mod;
	}
	int look_up(int x){
		int val=0;
		while(x){
			val+=query(1,n,A[top[x]],A[x],1);
			val%=mod;
			x=fa[top[x]];
		}
		return val;
	}
	void modify(int x){
		while(x){
			update(1,n,A[top[x]],A[x],1,1);
			x=fa[top[x]];
		}
	}
}T;
struct Ask{
	int pos,idx,node,o;
	Ask(int pos=0,int idx=0,int node=0,int o=0):pos(pos),idx(idx),node(node),o(o){}
}ask[maxn];
int asks=0;
void Read(){
	int f;
	scanf("%d%d",&n,&q);
	for(int i=2;i<=n;++i){
		scanf("%d",&f);
		fa[i]=f+1;
		tree.add_edge(f+1,i);
	}
	for(int i=1;i<=q;++i){
		int l,r,z;
		scanf("%d%d%d",&l,&r,&z);
		ask[++asks]=Ask(l-1+1,i,z+1,-1);
		ask[++asks]=Ask(r+1,i,z+1,1);
	}
}
int fin[maxn];
bool cmp(Ask i,Ask j){
	return i.pos<j.pos;
}
void solve(){
	tree.solve();
	sort(ask+1,ask+1+asks,cmp);
	int cur=0;
	for(int i=1;i<=asks;++i){
		while(cur<ask[i].pos){
			T.modify(cur+1);
			cur+=1;
		}
		fin[ask[i].idx]+=T.look_up(ask[i].node)*ask[i].o;
	}	
	for(int i=1;i<=q;++i)printf("%d\n",(fin[i]%mod+mod)%mod);
}

int main(){
	Read();
	solve();
	return 0;
}

[LNOI2014]LCA 樹鏈剖分 離線 前綴和 思維題