Submission #994010

#	Time	Username	Problem	Language	Result	Execution time	Memory
994010		aaaaaarroz	Closing Time (IOI23_closing)	C++17	0 / 100	859 ms	2097152 KiB

closing

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
vector<vector<pair<ll,ll>>>graph;
vector<bool> vis;
void dfs1(vector<ll> &dist, ll x, ll d){
    vis[x] = true;
    dist[x] = d;
    for (auto [y, w] : graph[x]){
        if (!vis[y]){
            dfs1(dist, y, d + w);
        }
    }
}
void dfs2(vector<pair<ll,ll>>dist, ll x, ll d){
    vis[x] = true;
    dist[x].first= d;
    for (auto [y, w] : graph[x]){
        if (!vis[y]){
            dfs2(dist, y, d + w);
        }
    }
}
ll max_score(int N, int X, int Y, ll K, vector<int> U, vector<int> V, vector<int> W){
	graph.assign(N,vector<pair<ll,ll>>());
	for(ll i=0;i<(N-1);i++){
		graph[U[i]].push_back({V[i],W[i]});
		graph[V[i]].push_back({U[i],W[i]});
	}
	vis.assign(N,false);
	vector<ll>distX(N);
	dfs1(distX,X,0);
	vis.assign(N,false);
	vector<ll>distY(N);
	dfs1(distY,Y,0);
	vis.assign(N,false);
	vector<pair<ll,ll>>orden;
	for(ll i=0;i<N;i++){
		pair<ll,ll>par;
		par.first=0;
		par.second=i;
		orden.push_back(par);
	}
	dfs2(orden,max_element(distX.begin(),distX.end())-distX.begin(),0);
	sort(orden.begin(),orden.end());
	ll pos_x;
	ll pos_y;
	for(ll i=0;i<N;i++){
		if(orden[i].second==X){
			pos_x=i+1;
		}
		else if(orden[i].second==Y){
			pos_y=i+1;
		}
	}
	vector<ll>prefix1(N+1,0);
	for(ll i=0;i<N;i++){
		prefix1[i+1]=(prefix1[i]+distX[orden[i].second]);
	}
	vector<ll>prefix2(N+1,0);
	for(ll i=0;i<N;i++){
		prefix2[i+1]=(prefix2[i]+distY[orden[i].second]);
	}
	ll ans=0;
	for(ll i=0;i<pos_x;i++){
		for(ll j=i;j<=N;j++){
			for(ll k=0;k<pos_y;k++){
				for(ll l=k;l<=N;l++){
					if((prefix1[j]-prefix1[i]+prefix2[l]-prefix2[k])<=K){
						ans=max((j-i+l-k),ans);
					}
				}
			}
		}
	}
	return ans;
}

Compilation message (stderr)

closing.cpp: In function 'll max_score(int, int, int, ll, std::vector<int>, std::vector<int>, std::vector<int>)':
closing.cpp:65:14: warning: 'pos_x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   65 |  for(ll i=0;i<pos_x;i++){
      |             ~^~~~~~
closing.cpp:67:16: warning: 'pos_y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   67 |    for(ll k=0;k<pos_y;k++){
      |               ~^~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 0 / 8
• Subtask 2: 0 / 9
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17