Submission #97359

#	Time	Username	Problem	Language	Result	Execution time	Memory
97359		TuGSGeReL	Race (IOI11_race)	C++14	9 / 100	3061 ms	10756 KiB

race

#include "race.h"
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define mp make_pair
#define pub push_back
#define pob pop_back()
#define ss second
#define ff first
#define mt make_tuple
#define pof pop_front()
#define fbo find_by_order
#define ook order_of_key
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
int i,ans=1e9,c[200001],used[200001];
vector<pair<int,int> >v[200001];
map<int,int>xox,yoy;
inline void dfs(int u, int par){
	for(auto x : v[u]) if(x.ff!=par) dfs(x.ff,u); 
	c[par]+=c[u];
}
inline void dfs1(int u, int parr, int s, int d){
	if(yoy.find(s) == yoy.end())yoy[s]=d;
	else yoy[s]=min(yoy[s],d);
	for(auto x : v[u]){
		if(x.ff!=parr){
			s+=x.ss;
			d++;
			dfs1(x.ff,u,s,d);
		}
	}
}
inline int fnd(int u , int sz){
	for(auto x : v[u]){
		if(!used[x.ff] && c[x.ff]>sz){
			c[u]-=c[x.ff];
			c[x.ff]+=c[u];
			return fnd(x.ff,sz);
		}
	}
	return u;
}
inline void solve(int at, int k){
	at=fnd(at,c[at]/2);
	used[at]=1;
	xox.clear();
	xox[0]=0;
	for(auto z : v[at]){
		if(used[z.ff]) continue;
		yoy.clear();
		dfs1(z.ff,at,z.ss,1);
		for(auto haha : yoy) if(xox.find(k-haha.ff)!=xox.end()) ans=min(ans,haha.ss+xox[k-haha.ff]);
		for(auto lol : yoy){
			if(xox.find(lol.ff)==xox.end()) xox[lol.ff]=lol.ss;
			else xox[lol.ff]=min(xox[lol.ff],lol.ss);
		}
	}
	for(auto hha : v[at]) if(!used[hha.ff]) solve(hha.ff,k);
}
int best_path(int N, int K, int H[][2], int L[]) {
	for(i=0;i<N-1;i++){
		c[i]=1;
		v[H[i][0]].pub(mp(H[i][1],L[i]));
		v[H[i][1]].pub(mp(H[i][0],L[i]));
	}
	c[N-1]=1;
	dfs(0,0);
	solve(0,K);
	if(ans==1e9) ans=-1;
	return ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57