Submission #975227

#	Time	Username	Problem	Language	Result	Execution time	Memory
975227		yoav_s	Road Closures (APIO21_roads)	C++17	7 / 100	80 ms	33108 KiB

roads

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<ll> v;
typedef vector<v> vv;
typedef vector<vv> vvv;
typedef pair<ll, ll> p;
typedef vector<p> vp;
typedef vector<vp> vvp;
typedef vector<vvp> vvvp;
typedef pair<ll, p> tri;
typedef vector<tri> vtri;
typedef vector<vtri> vvtri;
typedef vector<vvtri> vvvtri;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;

#define f first
#define s second
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(),(v).end()

const ll INF = 1e18;
const ll mod = 1e9 + 7;

#include "roads.h"

void solve(ll cur, vvp &graph, vp &res, ll k, vb &visited) //first = normal, second = without parent
{
    if (visited[cur]) return;
    visited[cur] = true;
    for (auto x : graph[cur]) solve(x.f, graph, res, k, visited);
    ll needToRemove = max(0ll, (ll)graph[cur].size() - k);
    ll needToRemove2 = max(0ll, needToRemove - 1);
    v add1, add2;
    ll sum = 0;
    for (auto x : graph[cur])
    {
        if (res[x.f].f == -1)
        {
          add1.pb(x.s); continue;
        }
        add1.pb(res[x.f].s - res[x.f].f + x.s);
        add2.pb(res[x.f].s - res[x.f].f + x.s);
        sum += res[x.f].f;
    }
    sort(all(add1)); sort(all(add2));
    res[cur] = p(sum, sum);
    for (ll i = 0; i < needToRemove; i++) res[cur].f += add1[i];
    for (ll i =0 ; i < needToRemove2; i++) res[cur].s += add2[i];
}

std::vector<long long> minimum_closure_costs(int N, std::vector<int> U, std::vector<int> V, std::vector<int> W) {
    vvp graph(N);
    for (ll i = 0; i < N - 1; i++)
    {
        graph[U[i]].eb(V[i],W[i]);
        graph[V[i]].eb(U[i],W[i]);
    }
    vector<long long> res(N, 0);
    ll sum = 0;
    for (auto x : W) sum += x;
    res[0] = sum;
    for (ll i =1; i <= 2; i++)
    {
        vb visited(N, false);
        vp dp(N, p(-1, -1));
        solve(0, graph, dp, i, visited);
        res[i] = dp[0].f;
    }
    return res;
}

/*
int main() {
  int N;
  assert(1 == scanf("%d", &N));

  std::vector<int> U(N - 1), V(N - 1), W(N - 1);
  for (int i = 0; i < N - 1; ++i) {
    assert(3 == scanf("%d %d %d", &U[i], &V[i], &W[i]));
  }

  std::vector<long long> closure_costs = minimum_closure_costs(N, U, V, W);
  for (int i = 0; i < static_cast<int>(closure_costs.size()); ++i) {
    if (i > 0) {
      printf(" ");
    }
    printf("%lld",closure_costs[i]);
  }
  printf("\n");
  return 0;
}
/**/

Compilation message (stderr)

roads.cpp:98:1: warning: "/*" within comment [-Wcomment]
   98 | /**/
      |

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