Submission #774099

#	Time	Username	Problem	Language	Result	Execution time	Memory
774099		Dzadzo	Fountain (eJOI20_fountain)	C++17	30 / 100	235 ms	31308 KiB

fountain

#include <bits/stdc++.h>
#define ll long long
#define int ll
#define pb push_back
#define S second
#define F first
#define pii pair<int,int>
#define vi vector <int>
#define vvi vector <vector<int>>
#define INF INT_MAX
#define MOD 1000000009
#define MAXN 100000
using namespace std;
int p[MAXN+1][20];
int sum[MAXN+1];
vvi adj(MAXN+1);
void dfs(int v,int par,int c[]){
	if (par==-1)sum[v]=0;else sum[v]=sum[par]+c[v];
	p[v][0]=par;
	for (int i=1;i<20;i++){
		if (p[v][i-1]<1)continue;
		p[v][i]=p[p[v][i-1]][i-1];
	}
	
	for (int u:adj[v])if (u!=par)dfs(u,v,c);
}
main() {
	ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
	int n,q;
	cin>>n>>q;
	int d[n+1],c[n+1];
	for (int i=1;i<=n;i++)cin>>d[i]>>c[i];
	int next[n+1];
	stack<pii> s;
	for (int i=n;i>=1;i--){
		while (!s.empty() && s.top().F<d[i])s.pop();
		if (s.empty())next[i]=0; else next[i]=s.top().S;	
		s.push({d[i],i});
	}
	
	for (int i=1;i<=n;i++){
		adj[next[i]].pb(i);
		adj[i].pb(next[i]);
	}
	memset(p,-1,sizeof(p));
	dfs(0,-1,c);
	while (q--){
		int v,vol;
		cin>>v>>vol;
		if (c[v]>=vol)cout<<v<<"\n";else{
			int cur=v;
			for (int i=19;i>=0;i--){
				if (p[cur][i]==-1 || p[cur][i]==0)continue;
				if (sum[v]-sum[p[p[cur][i]][0]]<vol)cur=p[cur][i];
			}
			cout<<p[cur][0]<<"\n";
		}
	}
}

Compilation message (stderr)

fountain.cpp:27:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   27 | main() {
      | ^~~~

• Subtask 1: 0 / 30
• Subtask 2: 30 / 30
• Subtask 3: 0 / 40