Submission #551222

#	Time	Username	Problem	Language	Result	Execution time	Memory
551222		Koosha_mv	Race (IOI11_race)	C++14	0 / 100	41 ms	56020 KiB

race

#include <bits/stdc++.h>
using namespace std;
#define dbgv(v) cout<<#v<<" = "; f(i,0,v.size()) cout<<v[i]<<" "; cout<<endl
#define dbga(a,x,y) cout<<#a<<" = "; f(i,x,y) cout<<a[i]<<" "; cout<<endl
#define erorp(x) cout<<#x<<"={"<<x.F<<" , "<<x.S<<"}"<<endl
#define eror(x) cout<<#x<<'='<<(x)<<endl
#define f_(i,a,b) for(int i=a;i>=b;i--)
#define f(i,a,b) for(int i=a;i<b;i++)
#define nb(x) __builtin_popcount(x)
#define all(v) v.begin(),v.end()
#define bit(n,k) (((n)>>(k))&1)
#define Add(x,y) x=(x+y)%mod
#define maxm(a,b) a=max(a,b)
#define minm(a,b) a=min(a,b)
#define lst(x) x[x.size()-1]
#define sz(x) int(x.size())
#define mp make_pair
#define ll long long
#define pb push_back
#define S second
#define F first
#include "race.h"

const int N=1e6+99;

int n,k,cent,ans=N,sz[N],vis[N],res[N];
int a[N][2],b[N];
vector<int> alh;
vector<pair<int,int>> vec,g[N];

void dfs1(int u,int p,int n){
	sz[u]=1;
	for(auto v : g[u]){
		if(p==v.F || vis[v.F]) continue ;
		dfs1(v.F,u,n);
		sz[u]+=sz[v.F];
	}
	if(2*sz[u]>=n && cent==-1) cent=u;
}
void dfs2(int u,int p,int h1,int h2){
	sz[u]=1;
	if(h2<=k){
		minm(ans,h1+res[k-h2]);
		alh.pb(h2);
		vec.pb({h2,h1});
	}
	else h2=k+1;
	for(auto v : g[u]){
		if(p==v.F || vis[v.F]) continue ;
		dfs2(v.F,u,h1+1,h2+v.S);
		sz[u]+=v.F;
	}
}
void solve(int rt,int n){
	cent=-1;
	dfs1(rt,rt,n);
	if(cent==-1) assert(0);
	res[0]=0;
	alh.clear();
	for(auto v : g[cent]){
		if(vis[v.F]) continue ;
		vec.clear();
		dfs2(v.F,rt,1,v.S);
		for(auto p : vec){
			minm(res[p.F],p.S);
		}
	}
	for(auto x : alh) res[x]=N;
	vis[cent]=1;
	for(auto v : g[cent]){
		if(vis[v.F]) continue ;
		solve(v.F,sz[v.F]);
	}
}
int best_path(int _n, int _k,int H[][2],int L[]){
	fill(res,res+N,N);
	n=_n,k=_k;
	f(i,0,n-1){
		int u=H[i][0],v=H[i][1],w=L[i];
		g[u].pb({v,w});
		g[v].pb({u,w});		
	}
	solve(1,n);
	if(ans==N) return -1;
	return ans;
}
/*
int32_t main(){
	int n,k;
	cin>>n>>k;
	f(i,0,n-1) cin>>a[i][0]>>a[i][1];
	f(i,0,n-1) cin>>b[i];
	cout<<best_path(n,k,a,b);
}
*/

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