Submission #764981

#	Time	Username	Problem	Language	Result	Execution time	Memory
764981		dxz05	Parkovi (COCI22_parkovi)	C++17	50 / 110	3066 ms	76788 KiB

Main

//#pragma GCC optimize("Ofast,O3,unroll-loops")
//#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair
#define BIT(x, i) (((x) >> (i)) & 1)
//#define endl '\n'

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 1e9 + 7;
const int N = 2e5 + 30;

int n;
vector<pair<int, int>> g[N];

ll dep[N];
int up[N][18];
ll sum[N][18];

void dfs0(int v, int p){
    up[v][0] = p;
    sum[v][0] = dep[v] - dep[p];
    for (int i = 1; i < 18; i++){
        int pp = up[v][i - 1];
        up[v][i] = up[pp][i - 1];
        sum[v][i] = sum[v][i - 1] + sum[pp][i - 1];
    }

    for (auto [u, w] : g[v]){
        if (u != p){
            dep[u] = dep[v] + w;
            dfs0(u, v);
        }
    }
}

bool deleted[N];

void dfs(int v, int p, ll dist){
    deleted[v] = true;

    for (auto [u, w] : g[v]){
        if (u == p) continue;
        if (w <= dist){
            dfs(u, v, dist - w);
        } else {
            break;
        }
    }
}

vector<int> parks(ll d){
    priority_queue<pair<ll, int>> pq;
    for (int i = 1; i <= n; i++) pq.emplace(dep[i], i);
    fill(deleted + 1, deleted + n + 1, false);

    vector<int> ans;
    while (!pq.empty()){
        int v = pq.top().second;
        if (deleted[v]){
            pq.pop();
            continue;
        }

        ll x = d;
        for (int i = 17; i >= 0; i--){
            if (sum[v][i] <= x){
                x -= sum[v][i];
                v = up[v][i];
            }
        }

        ans.push_back(v);
        dfs(v, -1, d);
    }

    return ans;
}

void solve(){
    int k;
    cin >> n >> k;

    for (int i = 1; i < n; i++){
        int u, v, w;
        cin >> u >> v >> w;
        g[u].emplace_back(v, w);
        g[v].emplace_back(u, w);
    }

    int root = 1;
    for (int i = 1; i <= n; i++){
        if (g[i].size() > 1) root = i;

        sort(all(g[i]), [&](auto x, auto y){
            return x.second < y.second;
        });

    }

    dfs0(root, root);

    vector<int> ans;

    ll l = 0, r = 2e14;
    while (l <= r){
        ll m = (l + r) >> 1;

        vector<int> p = parks(m);

        if (p.size() <= k){
            ans = p;
            r = m - 1;
        } else {
            l = m + 1;
        }
    }


    cout << ++r << endl;
    for (int x : ans) cout << x << ' ';

    int x = k - (int) ans.size();
    for (int i = 1; i <= n; i++){
        if (x == 0) break;
        int j = lower_bound(all(ans), i) - ans.begin();
        if (j == ans.size() || ans[j] != i){
            cout << i << ' ';
            x--;
        }
    }

    cout << endl;
}

int main(){
    clock_t startTime = clock();
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int test_cases = 1;
//    cin >> test_cases;

    for (int test = 1; test <= test_cases; test++){
        // cout << (solve() ? "YES" : "NO") << endl;
        solve();
    }

#ifdef LOCAL
    cerr << "Time: " << int((double) (clock() - startTime) / CLOCKS_PER_SEC * 1000) << " ms" << endl;
#endif

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:120:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  120 |         if (p.size() <= k){
      |             ~~~~~~~~~^~~~
Main.cpp:136:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  136 |         if (j == ans.size() || ans[j] != i){
      |             ~~^~~~~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:146:13: warning: unused variable 'startTime' [-Wunused-variable]
  146 |     clock_t startTime = clock();
      |             ^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 30 / 30
• Subtask 4: 0 / 60