Vasya and a Tree CodeForces

很好的思维

转化为对树上的深度差分

回朔的思想

对查询离线

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<queue>
#include<map>
#include<set>
#include<list>
#include<ctime>
#include<ctype.h>
#include<bitset>
#include<algorithm>
#include<numeric> //accumulate
#define endl "
"
#define fi first
#define se second
#define FOR(i,s,t) for(int i=(s);i<=(t);++i)
#define mem(a,b) memset(a,b,sizeof(a))
using namespace std;
const int maxn=300000+5;

int n;
vector<int> g[maxn];
vector<pair<int,int> > q[maxn];
long long add[maxn];
long long ans[maxn];
void dfs(int u,int pa,int dep,long long sum)
{
    for(auto i:q[u])
    {
        int l=dep,r=dep+i.fi+1;
        add[l]+=i.se;
        if(r<=n)
            add[r]-=i.se;
    }
    sum+=add[dep];
    ans[u]=sum;
    for(auto i:g[u])
    {
        if(i==pa)
            continue;
        dfs(i,u,dep+1,sum);
    }
    for(auto i:q[u])
    {
        int l=dep,r=dep+i.fi+1;
        add[l]-=i.se;
        if(r<=n)
            add[r]+=i.se;
    }
}
int main()
{

    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(false);
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    cin>>n;
    for(int i=1;i<n;i++)
    {
        int x,y;
        cin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int m;
    cin>>m;
    for(int i=0;i<m;i++)
    {
        int v,d,x;
        cin>>v>>d>>x;
        q[v].push_back({d,x});
    }
    dfs(1,0,0,0ll);
    for(int i=1;i<=n;i++)
        cout<<ans[i]<<' ';

}





/*
void read()
{

    char c = getchar();
    int x = 0;
    for (; (c < 48 || c>57); c = getchar());
    for (; c > 47 && c < 58; c = getchar())
    {
        x = (x << 1) + (x << 3) + c - 48;
    }
    return x;
}
*/