Submission #1194870

#	Time	Username	Problem	Language	Result	Execution time	Memory
1194870		irmuun	Dynamic Diameter (CEOI19_diameter)	C++20	24 / 100	5093 ms	9420 KiB

diameter

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

const ll N=1e5+5,Q=1e5+5;

ll n,q,W;
ll a[N],b[N],c[N];
ll mx=-1,node;
vector<ll>g[N];

void dfs(ll x,ll p,ll d){
	if(d>mx){
		mx=d;
		node=x;
	}
	for(ll i:g[x]){
		ll y=(a[i]==x?b[i]:a[i]),w=c[i];
		if(y!=p){
			dfs(y,x,d+w);
		}
	}
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin>>n>>q>>W;
	for(ll i=0;i<n-1;i++){
		cin>>a[i]>>b[i]>>c[i];
		g[a[i]].pb(i);
		g[b[i]].pb(i);
	}
	ll last=0;
	while(q--){
		ll d,e;
		cin>>d>>e;
		d=(d+last)%(n-1);
		e=(e+last)%W;
		c[d]=e;
		mx=-1;
		dfs(1,1,0);
		mx=-1,
		dfs(node,node,0);
		last=mx;
		cout<<last<<"\n";
	}
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 27