Codeforces Gym: 2003-2004 Winter Petrozavodsk Camp, Andrew Stankevich…

… Contest 4 (ASC 4)

Codeforces Gym/100198B.cpp

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+/**
+ * @file 100198B.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-01-11
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+class Dinic {
+   private:
+    struct Edge {
+        int to, cap, cost, rev;
+    };
+
+    vector<vector<Edge>> graph;
+    vector<vector<Edge>::iterator> cur;
+    vector<bool> vis;
+    queue<int> que;
+    int n, S, T;
+
+    int dfs(int p, int rest) {
+        if (p == T) return rest;
+        vis[p] = true;
+        int use = 0, c;
+        for (auto i = cur[p]; i != graph[p].end() && rest; i++) {
+            cur[p] = i;
+            if (!i->cap || vis[i->to]) continue;
+            c = dfs(i->to, min(rest, i->cap));
+            i->cap -= c, graph[i->to][i->rev].cap += c, use += c, rest -= c;
+        }
+        vis[p] = false;
+        return use;
+    }
+
+   public:
+    void resize(int _n) { return graph.resize((n = _n) + 1), cur.resize(n + 1), vis.resize(n + 1); }
+    void addEdge(int from, int to, int cap, int cost) {
+        return graph[from].push_back(Edge{to, cap, cost, (int)graph[to].size()}),
+               graph[to].push_back(Edge{from, 0, -cost, (int)graph[from].size() - 1});
+    }
+    void maxFlow(int _S, int _T) {
+        S = _S, T = _T;
+
+        sort(graph[S].begin(), graph[S].end(), [](const Edge& a, const Edge& b) { return a.cost > b.cost; });
+
+        vis[S] = true;
+        for (auto& e : graph[S]) {
+            for (int i = 1; i <= n; i++) cur[i] = graph[i].begin();
+            if (dfs(e.to, 1)) e.cap = 0, graph[e.to][e.rev].cap = 1;
+        }
+
+        return;
+    }
+    vector<int> getAns(int n) {
+        vector<int> ans(n + 1);
+        for (int i = 1; i <= n; i++)
+            for (auto e : graph[i])
+                if (e.to != S && !e.cap) ans[i] = e.to - n;
+        return ans;
+    }
+};
+
+void solve(void) {
+    int n;
+    cin >> n;
+
+    int S = 2 * n + 1, T = 2 * n + 2;
+    Dinic dnc;
+    dnc.resize(T);
+
+    for (int i = 1, v; i <= n; i++) cin >> v, dnc.addEdge(S, i, 1, v * v), dnc.addEdge(n + i, T, 1, 0);
+
+    for (int i = 1, s, x; i <= n; i++) {
+        cin >> s;
+        while (s--) cin >> x, dnc.addEdge(i, n + x, 1, 0);
+    }
+
+    dnc.maxFlow(S, T);
+
+    auto ret = dnc.getAns(n);
+
+    for (int i = 1; i <= n; i++) cout << ret[i] << ' ';
+    cout << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("beloved.in", "r", stdin), freopen("beloved.out", "w", stdout);
+#endif
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}

Codeforces Gym/100198E.cpp

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+/**
+ * @file 100198E.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-01-11
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 405
+
+typedef pair<int, int> pii;
+
+vector<pii> graph[maxn];
+vector<int> pos[maxn];
+int dis[maxn];
+
+void solve(void) {
+    int n, m, S, T;
+    cin >> n >> m >> S >> T;
+
+    for (int i = 1, x, y; i <= m; i++) cin >> x >> y, graph[x].emplace_back(y, i), graph[y].emplace_back(x, i);
+
+    queue<int> que;
+    que.push(S), dis[S] = 1;
+    while (!que.empty()) {
+        int p = que.front();
+        que.pop();
+        for (auto [q, id] : graph[p])
+            if (!dis[q]) dis[q] = dis[p] + 1, que.push(q);
+    }
+
+    for (int i = 1; i <= n; i++)
+        for (auto [j, id] : graph[i])
+            if (dis[i] < dis[j]) pos[dis[j]].push_back(id);
+
+    cout << dis[T] - 1 << endl;
+
+    for (int i = 2; i <= dis[T]; i++) {
+        cout << pos[i].size() << ' ';
+        for (auto id : pos[i]) cout << ' ' << id;
+        cout << endl;
+    }
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("defence.in", "r", stdin), freopen("defence.out", "w", stdout);
+#endif
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}

Codeforces Gym/100200A.cpp

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+/**
+ * @file 100200A.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-02-08
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+class Dinic {
+   private:
+    struct Edge {
+        int to, cap, rev;
+        bool mark;
+    };
+
+    vector<vector<Edge>> graph;
+    vector<vector<Edge>::iterator> cur;
+    vector<int> dist, rdist;
+    queue<int> que;
+    int n, S, T;
+
+    bool bfs(void) {
+        for (int i = 1; i <= n; i++) dist[i] = INT_MAX, cur[i] = graph[i].begin();
+        que.push(S), dist[S] = 0;
+        while (!que.empty()) {
+            int p = que.front();
+            que.pop();
+            for (auto i : graph[p])
+                if (i.cap && dist[i.to] > dist[p] + 1) dist[i.to] = dist[p] + 1, que.push(i.to);
+        }
+        return dist[T] != INT_MAX;
+    }
+    void rbfs(void) {
+        for (int i = 1; i <= n; i++) rdist[i] = INT_MAX;
+        que.push(T), rdist[T] = 0;
+        while (!que.empty()) {
+            int p = que.front();
+            que.pop();
+            for (auto i : graph[p])
+                if (graph[i.to][i.rev].cap && rdist[i.to] > rdist[p] + 1) rdist[i.to] = rdist[p] + 1, que.push(i.to);
+        }
+        return;
+    }
+    int64_t dfs(int p, int64_t rest) {
+        if (p == T) return rest;
+        int64_t use = 0, c;
+        for (auto i = cur[p]; i != graph[p].end() && rest; i++) {
+            cur[p] = i;
+            if (!i->cap || dist[i->to] != dist[p] + 1) continue;
+            if (!(c = dfs(i->to, min(rest, (int64_t)i->cap)))) dist[i->to] = -1;
+            i->cap -= c, graph[i->to][i->rev].cap += c, use += c, rest -= c;
+        }
+        return use;
+    }
+
+   public:
+    void resize(int _n) { return graph.resize((n = _n) + 1), cur.resize(n + 1), dist.resize(n + 1), rdist.resize(n + 1); }
+    void addEdge(int from, int to, int cap) {
+        return graph[from].push_back(Edge{to, cap, (int)graph[to].size(), false}),
+               graph[to].push_back(Edge{from, cap, (int)graph[from].size() - 1, false});
+    }
+    int64_t maxFlow(int _S, int _T) {
+        S = _S, T = _T;
+        int64_t ans = 0;
+        while (bfs()) ans += dfs(S, INT64_MAX);
+        return ans;
+    }
+    bool solve(void) {
+        bfs(), rbfs();
+        for (int p = 1; p <= n; p++)
+            for (auto &e : graph[p]) {
+                if (!e.cap && dist[p] != INT_MAX && rdist[e.to] != INT_MAX) e.mark = true;
+            }
+
+        for (int i = 1; i <= n; i++) dist[i] = 0;
+        que.push(S);
+        while (!que.empty()) {
+            int p = que.front();
+            que.pop();
+            for (auto i : graph[p])
+                if (!i.mark && !dist[i.to]) dist[i.to] = 1, que.push(i.to);
+        }
+
+        return dist[T];
+    }
+};
+
+void solve(void) {
+    int n, m, S, T;
+    cin >> n >> m >> S >> T;
+
+    Dinic dnc;
+    dnc.resize(n);
+    for (int i = 1, x, y, f; i <= m; i++) cin >> x >> y >> f, dnc.addEdge(x, y, f);
+
+    dnc.maxFlow(S, T);
+
+    cout << (dnc.solve() ? "AMBIGUOUS" : "UNIQUE") << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("attack.in", "r", stdin), freopen("attack.out", "w", stdout);
+#endif
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}