Submission #80179

#	Time	Username	Problem	Language	Result	Execution time	Memory
80179		farukkastamonuda	Race (IOI11_race)	C++14	21 / 100	3033 ms	11664 KiB

race

#include "race.h"
#include <bits/stdc++.h>
#define fi first
#define se second
#define lo long long 
#define inf 1000000000
#define md 1000000007
#define li 200005
#define li2 1000005
#define mp make_pair
#define pb push_back
using namespace std;
int n,k,vis[li],sub[li],mark[li2],ans=inf;
vector< pair<int,int> > v[li],vec;
vector<int> sil;
int calc(int node,int ata=-1){
	sub[node]=0;
	for(int i=0;i<(int)v[node].size();i++){
		int go=v[node][i].fi;
		if(vis[go]==0 && go!=ata) calc(go,node);
	}
	return ++sub[node];
}
int find(int node,int ata,int sz){
	for(int i=0;i<(int)v[node].size();i++){
		int go=v[node][i].fi;
		if(go!=ata && vis[go]==0 && sub[go]>sz/2){
			return find(go,node,sz);
		}
	}
	return node;
}
void dfs(int node,int ata,int val,int st){
	if(val==k) ans=min(ans,st);
	if(val<k){
		ans=min(ans,mark[k-val]+st);
		vec.pb(mp(val,st));
	}
	for(int i=0;i<(int)v[node].size();i++){
		int go=v[node][i].fi;
		if(go!=ata && vis[go]==0) dfs(go,node,val+v[node][i].se,st+1);
	}
}
void solve(int cur=1){
	//printf("*");
	int cen=find(cur,-1,calc(cur));
	sil.clear();
	for(int i=0;i<(int)v[cen].size();i++){
		int go=v[cen][i].fi;
		if(vis[go]==1) continue;
		vec.clear();
		dfs(go,cen,v[cen][i].se,1);
		for(int j=0;j<(int)vec.size();j++){
			mark[vec[j].fi]=min(mark[vec[j].fi],vec[j].se);
			sil.pb(vec[j].fi);
		}
	}
	for(int i=0;i<(int)sil.size();i++){
		mark[sil[i]]=inf;
	}
	vis[cen]=1;
	//sil.clear();
	for(int i=0;i<(int)v[cen].size();i++){
		int git=v[cen][i].fi;
		if(vis[git]==0) solve(git);
	}
}
int best_path(int N,int K,int H[][2],int L[]){
	n=N;
	k=K;
	for(int i=0;i<n-1;i++){
		int u=H[i][0]+1;
		int vv=H[i][1]+1;
		int c=L[i];
		v[u].pb(mp(vv,c));
		v[vv].pb(mp(u,c));
	}
	for(int i=0;i<=k;i++) mark[i]=inf;
	solve();
	if(ans>=inf) ans=-1;
	return ans;
}
//~ int main(){
	//~ G[0][0]=0,G[0][1]=1;
	//~ G[1][0]=1,G[1][1]=2;
	//~ G[2][0]=1,G[2][1]=3;
	//~ T[0]=1,T[1]=2,T[2]=4;
	//~ int ty=best_path(4,3,G,T);
	//~ printf("%d\n",ty);
	//~ return 0;
//}

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