Submission #865074

#	Time	Username	Problem	Language	Result	Execution time	Memory
865074		vjudge1	Birthday gift (IZhO18_treearray)	C++17	30 / 100	4072 ms	11152 KiB

treearray

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <cassert>
#include <iomanip>
#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <fstream>
#include <unordered_map>
using namespace std;

typedef long long ll;
typedef long double ld;

#define all(x) x.begin(),x.end()
#define pb push_back
#define ent "\n"

const int maxn = (int)2e5 + 13;
const ll inf = (long long)1e18 + 20;
const int mod = (int)1e9 + 7;

ll n,m,q;
ll a[maxn];
ll up[maxn][16];
ll sz[maxn];
ll b[maxn];
vector<int>g[maxn];

void calc(int v,int p ){
	for(int to : g[v]){
		if(to != p){
			up[to][0] = v;
			sz[to] = sz[v] + 1;
			calc(to,v); 
		}
	}
}

int lca(int x,int y){
	if(sz[x] > sz[y])swap(x,y);
	int dif = sz[y] - sz[x];
	for(int i = 0 ; i <= 15 ; i ++){
		if((dif >> i)&1){
			y = up[y][i];
		}
	}
	if(x == y)return x;
	for(int i = 15 ; i >= 0 ; i --){
		if(up[x][i]!=up[y][i] && min(up[x][i],up[y][i]) > 0){
			x = up[x][i];
			y = up[y][i];
		}
	}
	return up[x][0];
}

void solve(){
	cin >> n >> m >> q;
	map<int,int>mp;
	for(int i = 1 ; i < n ; i ++){
		int x,y;cin >> x >> y;
		g[x].pb(y);
		g[y].pb(x);
	}
	for(int i = 1 ; i <= m ; i ++){
		cin >> a[i];
		b[i] = a[i];
	}
	for(int i = 1 ; i <= n ; i ++){
		mp[i] = i;
	}
	calc(1,0);
	for(int i = 1 ; i <= 15 ; i ++){
		for(int j = 1 ; j <= n ; j ++){
			up[j][i] = up[up[j][i - 1]][i - 1];
		}
	}
	while(q--){
		int tp;cin >> tp;
		if(tp == 2){
			int l,r,v;cin >> l >> r >> v;
			int lc,ok = 0;
			for(int i = l ; i <= r ; i ++){
				for(int j = i ; j <= r ; j ++){
					if(i == j){
						lc = a[i];
					}
					lc = lca(lc,a[j]);
					if(lc == v){
						cout << i << ' ' << j << ent;
						ok = 1;
						break;
					}
				}
				if(ok)break;
			}
			if(!ok){
				cout << "-1 -1\n";
			}
		}
		else{
			int pos,v;cin >> pos >> v;
			mp[a[pos]] = v;
			a[pos] = v;

		}
	}
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while(t --){
		solve();
	}
	return 0;
}

Compilation message (stderr)

treearray.cpp: In function 'void solve()':
treearray.cpp:106:14: warning: 'lc' may be used uninitialized in this function [-Wmaybe-uninitialized]
  106 |      lc = lca(lc,a[j]);
      |           ~~~^~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44