Submission #728488

#	Time	Username	Problem	Language	Result	Execution time	Memory
728488		Rasoul006	Dreaming (IOI13_dreaming)	C++17	0 / 100	61 ms	15144 KiB

dreaming

#include "dreaming.h"

#include <bits/stdc++.h>

#define endl "\n"

#define F first

#define S second

#define pb push_back

typedef long long ll;

using namespace std;

const int N = 1e5+5;

const long long oo = 1e18 ;

vector <pair <ll,ll>> v[N] ;

ll n , m , ans , best , mx , dis[N] , len ;

bool vis[N] ;

pair <ll,ll> dfs (ll u , ll p)
{
    pair <ll,ll> ret = {0 , u} ;

    for (auto it : v[u])
    {
        if (it.F == p) continue ;

        pair <ll,ll> p = dfs(it.F , u) ;

        p.F += it.S ;

        ret = max(ret , p) ;
    }

    return ret ;
}

bool dfs2 (ll u , ll p , ll cost , ll gol)
{
    bool is = false ;

    for (auto it : v[u])
    {
        if (it.F != p)
            is |= dfs2(it.F , u , cost + it.S , gol) ;
    }

    is |= (u == gol);

    if (is)
        best = min (best , max(cost , len-cost));

    return is ;
}

ll p1 , p2 ;

ll get (ll p)
{
    p1 = dfs(p , p).S ;
    p2 = dfs(p1 , p1).S ;
    len = dfs(p1 , p1).F ;

    best = oo ;
    dfs2(p1 , p1 , 0 , p2) ;
    return best ;
}


int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
    n = N ; m = M ;

    for (int i = 0 ; i<m ; i++)
    {
        v[B[i]].pb({A[i] , T[i]});
        v[A[i]].pb({B[i] , T[i]});
    }

    ans += get(1) ;

    ll bans = len ;

    for (int i = 1 ; i<=n ; i++)
    {
        if (!vis[i])
        {
            ans += get(i) ;
            break ;
        }
    }

    bans = max(bans , len) ;

    return max(bans , ans + L) ;
}

• Subtask 1: 0 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 0 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23