Submission #343434

#	Time	Username	Problem	Language	Result	Execution time	Memory
343434		ijxjdjd	Election (BOI18_election)	C++14	0 / 100	23 ms	24300 KiB

election

#include <bits/stdc++.h>

#define FR(i, N) for (int i = 0; i < int(N); i++)
using namespace std;

using pi = pair<int, int>;

const int MAXN = (int)(7e4) + 5;
vector<int> adj[MAXN];
int par[MAXN];
set<int> minc[MAXN];
set<int> maxc[MAXN];
vector<int> color[MAXN];
vector<int> to[MAXN];
bool visited[MAXN];
int deg[MAXN];
unordered_map<int, int> condense;
int rev[MAXN];
pi merge(pi x, pi y) {
    if (minc[x.first].size() < minc[y.first].size()) {
        swap(x.first, y.first);
    }
    if (maxc[x.second].size() < minc[y.second].size()) {
        swap(x.second, y.second);
    }
    for (int i : minc[y.first]) {
        if (minc[x.first].count(i)) {
            minc[x.first].erase(i);
        }
        else {
            minc[x.first].insert(i);
        }
    }
    for (int i : maxc[y.second]) {
        if (maxc[x.second].count(i)) {
            maxc[x.second].erase(i);
        }
        else {
            maxc[x.second].insert(i);
        }
    }
    minc[y.first].clear();
    return x;
}
pi root(int n, int p) {
    pi cur = {n, n};
    par[n] = p;
    for (int e : adj[n]) {
        if (e != p) {
            cur = merge(cur, root(e, n));
        }
    }
    if (minc[cur.first].size() > 0) {
        int z = *(minc[cur.first].rbegin());
        if (!condense.count(z)) {
            rev[condense.size()] = z;
            condense[z] = condense.size();
        }
        color[condense[z]].push_back(n);
        to[n].push_back(condense[z]);
    }
    if (maxc[cur.second].size() > 0) {
        int z = *(maxc[cur.second].begin());
        if (!condense.count(z)) {
            rev[condense.size()] = z;
            condense[z] = condense.size();
        }
        color[condense[z]].push_back(n);
        to[n].push_back(condense[z]);
    }
    return cur;
}
int main()
{
//    freopen("input.in", "r", stdin);
    cin.tie(0);
    cin.sync_with_stdio(0);
    int N;
    cin >> N;
    FR(i, N-1) {
        int a, b;
        cin >> a >> b;
        a--; b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    int K;
    cin >> K;
    FR(i, K) {
        char c;
        int x, y, z;
        cin >> c;
        cin >> x >> y >> z;
        x--, y--;
        if (x != y) {
            if (c == 'm') {
                minc[x].insert(z);
                minc[y].insert(z);
            }
            else {
                maxc[x].insert(z);
                maxc[y].insert(z);
            }
        }
    }
    root(0, 0);
    queue<int> deq;
    unordered_set<int> unvis;
    for (int i = 0; i < condense.size(); i++) {
        deg[i] = color[i].size();
        if (deg[i] == 1) {
            deq.push(i);
        }
        else {
            unvis.insert(i);
        }
    }
    while (unvis.size() > 0) {

        while (deq.size() > 0) {
            int next = deq.front(); deq.pop();
            for (int j : color[next]) {
                if (!visited[j]) {
                    visited[j] = true;
                    cout << j+1 << " " << par[j]+1 << " " << rev[next] << '\n';
                    for (int e : to[j]) {
                        deg[e]--;
                        if (deg[e] == 1 && unvis.count(e)) {
                            deq.push(e);
                            unvis.erase(e);
                        }
                    }
                    break;
                }
            }
        }
        if (unvis.size() > 0) {
            int j = *unvis.begin();
            unvis.erase(j);
            deq.push(j);
        }
    }
    for (int i = 1; i < N; i++) {
        if (!visited[i]) {
            if (to[i].size() > 0) {
                cout << par[i]+1 << " " << i+1 << " " << rev[to[i][0]] << '\n';
            }
            else {
                cout << par[i]+1 << " " << i+1 << " " << 1 << '\n';
            }
        }
    }
    return 0;
}

Compilation message (stderr)

election.cpp: In function 'int main()':
election.cpp:109:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::unordered_map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  109 |     for (int i = 0; i < condense.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18