Add a bunch of other problems

ITMO Academy: pilot course - Disjoint Sets Union - Step 1/E. Monkeys.cpp

@@ -0,0 +1,180 @@
+/* Problem URL: https://codeforces.com/edu/course/2/lesson/7/1/practice/contest/289390/problem/E */
+
+#include <bits/stdc++.h>
+#include <ext/pb_ds/assoc_container.hpp>
+#include <ext/pb_ds/tree_policy.hpp>
+
+using namespace std;
+using namespace __gnu_pbds;
+
+template <class T, class comp = less<>>
+using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (int i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, m;
+    cin >> n >> m;
+
+    V<array<int, 2>> graph(n);
+
+    rep(i, n) {
+        int a, b;
+        cin >> a >> b;
+
+        graph[i] = {a - 1, b - 1};
+    }
+
+    V<tuple<int, int, int>> edges(m);
+
+    while (m--) {
+        int i, p;
+        cin >> i >> p;
+        i--, p--;
+
+        edges[m] = {i, p, graph[i][p]};
+        graph[i][p] = -1;
+    }
+
+    vi dsu(n);
+    V<set<int>> nodes(n);
+    rep(i, n) {
+        dsu[i] = i;
+        nodes[i].insert(i);
+    }
+
+    function<int(int)> find_p = [&](int i) {
+        if (dsu[i] == i) {
+            return i;
+        }
+        return dsu[i] = find_p(dsu[i]);
+    };
+
+    auto join = [&](int a, int b) {
+        a = find_p(a);
+        b = find_p(b);
+
+        if (a == b) {
+            return;
+        }
+
+        if (a > b) {
+            swap(a, b);
+        }
+
+        if (nodes[a].size() < nodes[b].size()) {
+            swap(nodes[a], nodes[b]);
+        }
+
+        repv(i, nodes[b]) {
+            nodes[a].insert(i);
+        }
+        nodes[b].clear();
+
+        dsu[b] = a;
+    };
+
+    rep(i, n) {
+        if(graph[i][0] >= 0) {
+            join(i, graph[i][0]);
+        }
+
+        if (graph[i][1] >= 0) {
+            join(i, graph[i][1]);
+        }
+    }
+
+    vi ans(n, -1);
+
+    rep(k, edges.size()) {
+        auto [i, p, j] = edges[k];
+
+        i = find_p(i);
+        j = find_p(j);
+
+        if (i != j) {
+            if (i > j) {
+                swap(i, j);
+            }
+
+            if (i == 0) {
+                repv(l, nodes[j]) {
+                    ans[l] = edges.size() - k - 1;
+                }
+            }
+
+            join(i, j);
+        }
+    }
+
+    repv(i, ans) {
+        cout << i << '\n';
+    }
+}