Submission #559490

#	Time	Username	Problem	Language	Result	Execution time	Memory
559490		fcmalkcin	Road Closures (APIO21_roads)	C++17	24 / 100	2095 ms	32664 KiB

roads

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

#define ll  long long
#define pll pair<ll,ll>
#define ff first
#define ss second
#define pb push_back
#define endl "\n"
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

const ll maxn=5e5+50;
const ll mod=1e9+7  ;
const ll base=1e18;


/// i believe myself
/// goal 0/7

#include "roads.h"

vector<pll> adj[maxn];
ll dp[maxn][2];
ll k;
void dfs(ll u,ll par,ll w)
{
    ll cnt=0;
    ll sl=0;

    dp[u][0]+=w;
    if (k==0) dp[u][1]=base;
    vector<ll> vt;
    for (auto p:adj[u])
    {
        ll to=p.ff;
        if (to==par) continue;
        dfs(to,u,p.ss);
        if (dp[to][0]<=dp[to][1])
        {
            dp[u][0]+=dp[to][0];
            dp[u][1]+=dp[to][0];
        }
        else
        {
            sl++;
            dp[u][0]+=dp[to][1];
            dp[u][1]+=dp[to][1];
            vt.pb(dp[to][0]-dp[to][1]);
        }
    }
    sort(vt.begin(),vt.end());
    ll p=sl-k;
    for (int i=0;i<p;i++) dp[u][0]+=vt[i];
   if (k) for (int i=0;i<p+1;i++) dp[u][1]+=vt[i];
}
vector<ll> minimum_closure_costs(int N, vector<int> U,vector<int> V,vector<int> W)
{
    ll n=N;
    for (int i=0;i<U.size();i++)
    {
        adj[U[i]+1].pb(make_pair(V[i]+1,W[i]));
        adj[V[i]+1].pb(make_pair(U[i]+1,W[i]));
    }
    vector<ll> res;
    for (int i=0;i<=n-1;i++)
    {
        for (int t=0;t<=n;t++) for (int p=0;p<=1;p++) dp[t][p]=0;
        k=i;
        dfs(1,0,0);
        res.pb(dp[1][0]);
    }
    return res;
}

/*int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    if (fopen("t.inp", "r"))
    {
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    ll n;
    vector<ll> p,p1,p2;
    cin>> n;
    for (int i=1;i<=n-1;i++)
    {
        ll x, y, w;
        cin>> x>> y>> w;
        p.pb(x);
        p1.pb(y);
        p2.pb(w);
    }
    vector<ll> res=minimum_closure_costs(n, p,p1,p2);
    for (auto to:res) cout <<to<<" ";
}*/
/*
5
0 1 1
0 2 4
0 3 3
2 4 2
*/

Compilation message (stderr)

roads.cpp: In function 'void dfs(long long int, long long int, long long int)':
roads.cpp:27:8: warning: unused variable 'cnt' [-Wunused-variable]
   27 |     ll cnt=0;
      |        ^~~
roads.cpp: In function 'std::vector<long long int> minimum_closure_costs(int, std::vector<int>, std::vector<int>, std::vector<int>)':
roads.cpp:59:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |     for (int i=0;i<U.size();i++)
      |                  ~^~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22