Submission #566719

#	Time	Username	Problem	Language	Result	Execution time	Memory
566719		Ooops_sorry	Road Closures (APIO21_roads)	C++14	0 / 100	2089 ms	19556 KiB

roads

#include<bits/stdc++.h>
#ifndef LOCAL
    #include "roads.h"
#endif

#define ld long double
#define ll long long
#define pb push_back

using namespace std;

const int N = 1e5 + 10;
const ll INF = 1e18;
vector<pair<int,int>> g[N];
ll e[N], dp[N][2];
int k, n;

void dfs(int v, int p) {
    vector<int> arr;
    ll sum = 0;
    for (auto to : g[v]) {
        if (to.first != p) {
            e[to.first] = to.second;
            dfs(to.first, v);
            arr.pb(to.first);
            sum += dp[to.first][0];
        }
    }
    sort(arr.begin(), arr.end(), [&](int u, int v){return dp[u][1] + e[u] - dp[u][0] > dp[v][1] + e[v] - dp[v][0];});
    if (arr.size() < k) {
        for (auto to : arr) {
            sum += dp[to][1] + e[to] - dp[to][0];
        }
        dp[v][0] = dp[v][1] = sum;
    } else {
        if (k == 0) {
            dp[v][0] = sum;
        } else {
            for (int i = 1; i <= k; i++) {
                int to = arr[i - 1];
                sum += dp[to][1] + e[to] - dp[to][0];
                if (i < k) {
                    dp[v][1] = max(dp[v][1], sum);
                } else {
                    dp[v][0] = sum;
                }
            }
            dp[v][0] = max(dp[v][1], dp[v][0]);
        }
    }
}

vector<long long> minimum_closure_costs(int N, vector<int> u, vector<int> v, vector<int> w) {
    n = N;
    ll sum = 0;
    for (int i = 0; i < n - 1; i++) {
        g[u[i]].pb({v[i], w[i]});
        g[v[i]].pb({u[i], w[i]});
        sum += w[i];
    }
    vector<ll> ans;
    for (k = 0; k < n; k++) {
        for (int i = 0; i < n; i++) {
            dp[i][0] = dp[i][1] = -INF;
        }
        dfs(0, -1);
        ans.pb(sum - dp[0][0]);
    }
    return ans;
}

#ifdef LOCAL

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;
}

#endif

Compilation message (stderr)

roads.cpp: In function 'void dfs(int, int)':
roads.cpp:30:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   30 |     if (arr.size() < k) {
      |         ~~~~~~~~~~~^~~

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