Submission #1220983

#	Time	Username	Problem	Language	Result	Execution time	Memory
1220983		toast12	Experimental Charges (NOI19_charges)	C++20	100 / 100	28 ms	6216 KiB

charges

#include <bits/stdc++.h>
using namespace std;

struct DSU {
    vector<int> size, link, charge;
    vector<vector<int>> adj;
    DSU(int sz) {
        size.resize(sz+1, 1);
        link.resize(sz+1);
        charge.resize(sz+1, 1);
        adj.resize(sz+1);
        iota(link.begin(), link.end(), 0);
    }
    int find(int x) {
        while (x != link[x]) x = link[x];
        return x;
    }
    bool same(int a, int b) {
        return find(a) == find(b);
    }
    void unite(int a, int b, bool res) {
        if (same(a, b)) return;
        if (size[find(a)] < size[find(b)]) swap(a, b);
        if ((charge[a] == charge[b] && res) || (charge[a] != charge[b] && !res)) {
            b = find(b);
            dfs(b, b);
        }
        a = find(a);
        b = find(b);
        size[a] += size[b];
        link[b] = a;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    void dfs(int cur, int p) {
        charge[cur] = 1-charge[cur];
        for (auto e : adj[cur]) {
            if (e != p) dfs(e, cur);
        }
    }
};

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    int n, q;
    cin >> n >> q;
    DSU d(n);
    while (q--) {
        char c;
        int a, b;
        cin >> c >> a >> b;
        if (c == 'R') d.unite(a, b, 0);
        else if (c == 'A') d.unite(a, b, 1);
        else {
            if (d.same(a, b)) {
                if (d.charge[a] == d.charge[b]) cout << "R\n";
                else cout << "A\n";
            }
            else cout << "?\n";
        }
    }
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 14 / 14
• Subtask 4: 12 / 12
• Subtask 5: 25 / 25
• Subtask 6: 31 / 31