Submission #561689

#	Time	Username	Problem	Language	Result	Execution time	Memory
561689		piOOE	Road Closures (APIO21_roads)	C++17	0 / 100	376 ms	21004 KiB

roads

#include "roads.h"

#include <bits/stdc++.h>

using namespace std;

#define all(x) begin(x), end(x)

typedef long long ll;

const int N = 100001;
int A[N], B[N], W[N], n, depth[N];
vector<int> g[N];
set<int> deg[N];
set<pair<int, int>> e;
bool used[N], kid[N];
int cnt = 0, pp[N];

void dfs(int v, int p) {
    pp[v] = p;
    for (int to: g[v]) {
        if (to != p) {
            depth[to] = depth[v] + 1;
            dfs(to, v);
        }
    }
}

vector<ll> minimum_closure_costs(int nn, vector<int> uu, vector<int> vv, vector<int> ww) {
    n = nn;
    for (int i = 0; i < n - 1; ++i) {
        A[i] = uu[i], B[i] = vv[i], W[i] = ww[i];
        g[A[i]].push_back(B[i]);
        g[B[i]].push_back(A[i]);
        e.insert(make_pair(A[i], B[i]));
    }
    vector<ll> ans(n);
    ans[0] = 0;
    vector<int> ord(n);
    iota(all(ord), 0);
    sort(all(ord), [](int i, int j) {
        return g[i].size() > g[j].size();
    });
    dfs(0, -1);
    for (int k = 1; k < n; ++k) {
        vector<int> now;
        for (int i: ord) {
            if (g[i].size() < k - 1) break;
            if (g[i].size() < k) {
                for (int x: g[i]) {
                    if ((e.count({x, i}) || e.count({i, x})) && g[x].size() >= k) {
                        deg[x].insert(i);
                    }
                }
                continue;
            }
            now.push_back(i);
        }
        sort(all(now), [](int i, int j) {
            return depth[i] > depth[j];
        });
        ans[k] = ans[k - 1];
        for (int i: now) {
            if (kid[i] || (pp[i] != -1 && kid[pp[i]])) continue;
            for (int to : deg[i]) {
                ++ans[k];
                e.erase({to, i});
                e.erase({i, to});
                kid[i] = true;
                break;
            }
            if (!deg[i].empty()) {
                deg[i].erase(begin(deg[i]));
            }
        }
        for (int i: now) {
            if (used[i] || pp[i] == -1 || kid[pp[i]] || kid[i]) continue;
            used[i] = true;
            kid[pp[i]] = true;
            deg[i].erase(pp[i]);
            deg[pp[i]].erase(i);
            e.erase({i, pp[i]});
            e.erase({pp[i], i});
            ++ans[k];
        }
        for (int i: now) {
            if (pp[i] != -1) {
                kid[pp[i]] = false;
            }
            kid[i] = false;
        }
    }
    for (int i = 0; i < n; ++i) ans[i] = n - 1 - ans[i];
    return ans;
}

Compilation message (stderr)

roads.cpp: In function 'std::vector<long long int> minimum_closure_costs(int, std::vector<int>, std::vector<int>, std::vector<int>)':
roads.cpp:48:29: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   48 |             if (g[i].size() < k - 1) break;
      |                 ~~~~~~~~~~~~^~~~~~~
roads.cpp:49:29: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |             if (g[i].size() < k) {
      |                 ~~~~~~~~~~~~^~~
roads.cpp:51:77: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   51 |                     if ((e.count({x, i}) || e.count({i, x})) && g[x].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