Submission #566789

#	Time	Username	Problem	Language	Result	Execution time	Memory
566789		Ooops_sorry	Road Closures (APIO21_roads)	C++14	0 / 100	138 ms	30152 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, ll>> g[N];
vector<bool> used(N);
vector<ll> arr[N];
int n, k;
ll dp[N][2];

struct Fenwick {
    vector<ll> t;
    void build(int n) {
        t.resize(n);
    }
    void inc(int i, ll val) {
        t[i] += val;
        for (; i < t.size(); i = (i | (i + 1))) {
            t[i] += val;
        }
    }
    ll get(int r) {
        ll ans = 0;
        for (; r >= 0; r = (r & (r + 1)) - 1) {
            ans += t[r];
        }
        return ans;
    }
} sum[N], cnt[N];

void add(int v, ll a) {
    int j = lower_bound(arr[v].begin(), arr[v].end(), a) - arr[v].begin();
    sum[v].inc(j, a);
    cnt[v].inc(j, 1);
}

ll get(int v, int need) {
    need = (int)(g[v].size()) - need;
    if (need <= 0) return 0;
    int l = -1, r = arr[v].size();
    while (r - l > 1) {
        int mid = (r + l) / 2;
        if (cnt[v].get(mid) >= need) {
            r = mid;
        } else {
            l = mid;
        }
    }
    return sum[v].get(r - 1) + (arr[v][r] * (need - cnt[v].get(r - 1)));
}

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

vector<long long> minimum_closure_costs(int N, vector<int> u, vector<int> v, vector<int> w) {
    n = N;
    ll res = 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]});
        res += w[i];
    }
    vector<vector<int>> vert(n);
    vector<int> ord(n);
    iota(ord.begin(), ord.end(), 0);
    for (int i = 0; i < n; i++) {
        sort(g[i].begin(), g[i].end(), [&](pair<int,int> a, pair<int,int> b){return g[a.first].size() > g[b.first].size();});
        for (auto to : g[i]) {
            arr[i].pb(to.second);
        }
        sort(arr[i].begin(), arr[i].end());
        arr[i].erase(unique(arr[i].begin(), arr[i].end()), arr[i].end());
        sum[i].build((int)arr[i].size());
        cnt[i].build((int)arr[i].size());
        vert[g[i].size()].pb(i);
    }
    vector<ll> ans(n);
    ans[0] = res;
    for (k = 1; k < n; k++) {
        for (auto v : vert[k]) {
            for (auto to : g[v]) {
                add(to.first, to.second);
            }
        }
        for (auto to : ord) {
            if (g[to].size() <= k) break;
            used[to] = 0;
        }
        for (auto to : ord) {
            if (g[to].size() <= k) break;
            if (!used[to]) {
                dfs(to, -1);
                ans[k] += dp[to][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 member function 'void Fenwick::inc(int, long long int)':
roads.cpp:27:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |         for (; i < t.size(); i = (i | (i + 1))) {
      |                ~~^~~~~~~~~~
roads.cpp: In function 'void dfs(int, int)':
roads.cpp:66:49: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   66 |         if (to.first != p && g[to.first].size() > k) {
      |                              ~~~~~~~~~~~~~~~~~~~^~~
roads.cpp:79:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |         if (i < arr.size()) sum += arr[i];
      |             ~~^~~~~~~~~~~~
roads.cpp: In function 'std::vector<long long int> minimum_closure_costs(int, std::vector<int>, std::vector<int>, std::vector<int>)':
roads.cpp:114:30: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  114 |             if (g[to].size() <= k) break;
      |                 ~~~~~~~~~~~~~^~~~
roads.cpp:118:30: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  118 |             if (g[to].size() <= k) break;
      |                 ~~~~~~~~~~~~~^~~~

• 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