Submission #286459

#	Time	Username	Problem	Language	Result	Execution time	Memory
286459		errorgorn	Dynamic Diameter (CEOI19_diameter)	C++14	100 / 100	814 ms	57852 KiB

diameter

//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

struct node{
	int s,e,m;
	ll a=0,b=0,c=0,ab=0,bc=0,abc=0,lazy=0;
	node *l,*r;
	
	node (int _s,int _e){
		s=_s,e=_e,m=s+e>>1;
		
		if (s!=e){
			l=new node(s,m);
			r=new node(m+1,e);
		}
	}
	
	void propo(){
		if (lazy){
			a+=lazy;
			b-=lazy*2;
			c+=lazy;
			ab-=lazy;
			bc-=lazy;
			
			if (s!=e){
				l->lazy+=lazy;
				r->lazy+=lazy;
			}
			
			lazy=0;
		}
	}
	
	void update(int i,int j,ll k){
		if (s==i && e==j) lazy+=k;
		else{
			if (j<=m) l->update(i,j,k);
			else if (m<i) r->update(i,j,k);
			else l->update(i,m,k),r->update(m+1,j,k);
			
			l->propo(),r->propo();
			
			a=max(l->a,r->a);
			b=max(l->b,r->b);
			c=max(l->c,r->c);
			ab=max({l->ab,r->ab,l->a+r->b});
			bc=max({l->bc,r->bc,l->b+r->c});
			abc=max({l->abc,r->abc,l->a+r->bc,l->ab+r->c});
		}
	}
} *root=new node(0,200005);

ll n,q,w0;

vector<ii> al[100005];
ll w[100005];
int id[100005]; //assoc weight to node

int in[100005];
int out[100005];

int TIME=0;

void dfs(int i,int p){
	in[i]=TIME++;
	for (auto &it:al[i]){
		if (it.fi==p) continue;
		dfs(it.fi,i);
		id[it.se]=it.fi;
		out[i]=TIME++;
	}
	if (out[i]==0) out[i]=in[i];
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	
	cin>>n>>q>>w0;
	
	ll a,b,c;
	rep(x,0,n-1){
		cin>>a>>b>>c;
		al[a].push_back(ii(b,x));
		al[b].push_back(ii(a,x));
		
		w[x]=c;
	}
	dfs(1,-1);
	
	rep(x,0,n-1){
		root->update(in[id[x]],out[id[x]],w[x]);
	}
	
	ll lastans=0;
	while (q--){
		cin>>a>>b;
		a=(a+lastans)%(n-1),b=(b+lastans)%w0;
		
		root->update(in[id[a]],out[id[a]],b-w[a]);
		w[a]=b;
		
		lastans=root->abc;
		cout<<lastans<<endl;
	}
}

Compilation message (stderr)

diameter.cpp: In constructor 'node::node(int, int)':
diameter.cpp:34:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   34 |   s=_s,e=_e,m=s+e>>1;
      |               ~^~

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