Submission #1093761

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093761		asli_bg	Race (IOI11_race)	C++11	21 / 100	87 ms	40516 KiB

race

#pragma GCC optimize("O3,unroll-loops")

#include "race.h"

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define all(x) x.begin(),x.end()
#define pb push_back
 
#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)
#define cont(x) {for(auto el:x) cout<<el<<' ';cout<<endl;}
#define contp(x) {for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;}
#define sp <<" "<<
#define mid (l+r)/2
#define endl '\n'
 
#define DEBUG(X) {cout<<#X<<' '<<(X)<<endl;}
 
#define carp(x,y) ((x%MOD)*(y%MOD))%MOD
#define topla(x,y) ((x%MOD)+(y%MOD))%MOD
 
typedef vector<int> vi;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef vector<pii> vii;
typedef vector<bool> vb;

const int MAXN=3e5+5;
const int INF=INT_MAX;
const int MOD=1e9+7;
 
vii adj[MAXN];
int n,k;
int res;
pii t[MAXN];

set<pii> s[MAXN];

void merge(set<pii>& a,set<pii>& b, int nd){
    if(a.size()<b.size()) swap(a,b);
    //setteki elemanlar--> {dist,edge sayisi}
    //adjdeki elemanlar--> {kom,dist}
    int aranan=k+2*t[nd].se;
    int cikar=t[nd].fi;

    //önce cevabı bul
    for(auto el:b){
        auto deg=aranan-el.fi;
        auto it=a.lower_bound({deg,0});
        auto bir=(*it).fi; //distance
        auto iki=(*it).se; //no of edges
        if(bir==deg){
            res=min(res,iki+el.se-2*cikar);
        }
    }

    //sonra insertle
    for(auto el:b) a.insert(el);
}

void dfs(int nd,int ata,int h,int edg){
    t[nd]={edg,h};

    for(auto el:adj[nd]){
        int kom=el.fi;
        int cost=el.se;
        if(kom!=ata){
            dfs(kom,nd,h+cost,edg+1);
            merge(s[nd],s[kom],nd);
        }
    }

    int aranan=k+t[nd].se;
    int cikar=t[nd].fi;
    auto it=s[nd].lower_bound({aranan,0});
    if((*it).fi==aranan){
        res=min(res,(*it).se-cikar);
    }
    
    s[nd].insert({t[nd].se,t[nd].fi});
}


int best_path(int N, int K, int H[][2], int L[]){
    //#define int long long
    res=INF;
    k=K;
    n=N;
    FOR(i,n-1){
        adj[H[i][0]+1].pb({H[i][1]+1,L[i]});
        adj[H[i][1]+1].pb({H[i][0]+1,L[i]});
    }
    
    dfs(1,0,0,0);

    //#undef int

    if(res==INF) res=-1;
    return res;
}

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