Codeforces Gym: 2002-2003 Winter Petrozavodsk Camp, Andrew Stankevich…

… Contest 1 (ASC 1)

Codeforces Gym/100199A.py

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+import math;
+
+fin = open("china.in", "r")
+fout = open("china.out", "w")
+
+n = int(fin.read())
+
+m = n // 2
+
+while math.gcd(n, m) != 1:
+    m -= 1
+
+fout.write(str(m))

Codeforces Gym/100199B.cpp

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+/**
+ * @file 100199B.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-01-10
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxm 40005
+
+int cap[maxm];
+
+class Dinic {
+   private:
+    struct Edge {
+        int to, cap, rev, id;
+    };
+
+    vector<vector<Edge>> graph;
+    vector<vector<Edge>::iterator> cur;
+    vector<int> dist, preF;
+    int n, S, T;
+
+    bool bfs(void) {
+        for (int i = 1; i <= n; i++) dist[i] = INT_MAX, cur[i] = graph[i].begin();
+        queue<int> que;
+        dist[S] = 0, que.push(S);
+        while (!que.empty()) {
+            int p = que.front();
+            que.pop();
+            for (auto i : graph[p])
+                if (i.cap > 0 && dist[i.to] == INT_MAX) dist[i.to] = dist[p] + 1, que.push(i.to);
+        }
+        return dist[T] != INT_MAX;
+    }
+
+    int dfs(int p, int rest) {
+        if (p == T) return rest;
+        int c, flow = 0;
+        for (auto i = cur[p]; i != graph[p].end() && rest; i++) {
+            cur[p] = i;
+            if (i->cap == 0 || dist[i->to] != dist[p] + 1) continue;
+            if (!(c = dfs(i->to, min(rest, i->cap)))) dist[i->to] = -1;
+            flow += c, rest -= c, i->cap -= c, graph[i->to][i->rev].cap += c;
+        }
+        return flow;
+    }
+
+   public:
+    void resize(int _n) { return graph.resize((n = _n) + 1), cur.resize(n + 1), dist.resize(n + 1), preF.resize(n + 1); }
+    void addEdge(int from, int to, int cap, int low, int id) {
+        preF[from] -= low, preF[to] += low, cap -= low, ::cap[id] += low;
+        return graph[from].push_back(Edge{to, cap, (int)graph[to].size(), id}),
+               graph[to].push_back(Edge{from, 0, (int)graph[from].size() - 1, 0});
+    }
+    bool maxFlow(int _S, int _T) {
+        S = _S, T = _T;
+
+        for (int i = 1; i <= n; i++) {
+            if (i == S || i == T) continue;
+            if (preF[i] > 0) addEdge(S, i, preF[i], 0, 0);
+            if (preF[i] < 0) addEdge(i, T, -preF[i], 0, 0);
+        }
+
+        while (bfs()) dfs(S, INT_MAX);
+
+        for (int i = 1; i <= n; i++)
+            for (auto e : graph[i])
+                if (e.id) cap[e.id] += graph[e.to][e.rev].cap;
+
+        for (auto e : graph[S])
+            if (e.cap) return false;
+        return true;
+    }
+};
+
+void solve(void) {
+    int n, m;
+    cin >> n >> m;
+
+    Dinic dnc;
+    dnc.resize(n + 2);
+    for (int i = 1, x, y, c, l; i <= m; i++) cin >> x >> y >> l >> c, dnc.addEdge(x, y, c, l, i);
+
+    if (!dnc.maxFlow(n + 1, n + 2)) return cout << "NO" << endl, void();
+
+    cout << "YES" << endl;
+    for (int i = 1; i <= m; i++) cout << cap[i] << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("cooling.in", "r", stdin), freopen("cooling.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/100199C.cpp

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+/**
+ * @file 100199C.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-01-10
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 500005
+
+int fa[maxn], deg[maxn];
+bool vis[maxn];
+
+void solve(void) {
+    int n;
+    cin >> n;
+
+    for (int i = 2; i <= n; i++) cin >> fa[i], deg[fa[i]]++;
+
+    queue<int> que;
+    for (int i = 1; i <= n; i++)
+        if (!deg[i]) que.push(i);
+
+    vector<int> ans;
+    while (!que.empty()) {
+        int p = que.front();
+        que.pop();
+        if (p == 1) break;
+
+        if (!vis[p] && !vis[fa[p]]) vis[p] = vis[fa[p]] = true, ans.push_back(p);
+        if (!--deg[fa[p]]) que.push(fa[p]);
+    }
+
+    cout << ans.size() * 1000 << endl;
+    sort(ans.begin(), ans.end());
+    for (auto i : ans) cout << i << ' ';
+    cout << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("grant.in", "r", stdin), freopen("grant.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/100199D.cpp

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+/**
+ * @file 100199D.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-01-10
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+void solve(void) {
+    int n, m;
+    cin >> n >> m;
+
+    vector<int> cnt(n + 1);
+    for (int i = 1, x, y; i <= m; i++) cin >> x >> y, cnt[x]++, cnt[y]++;
+    int64_t ans = 0;
+    for (int i = 1; i <= n; i++) ans += (int64_t)cnt[i] * cnt[i];
+    cout << ans << endl;
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("matrix.in", "r", stdin), freopen("matrix.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/100199E.cpp

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+/**
+ * @file 100199E.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-01-10
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+int mod;
+
+class Matrix {
+   private:
+    vector<vector<int>> mat;
+    int n, m;
+
+   public:
+    vector<int>& operator[](size_t i) { return mat[i]; }
+    int get(size_t i, size_t j) const { return mat[i][j]; }
+
+    void resize(int _n, int _m) { return mat.resize(n = _n, vector<int>(m = _m, 0)); }
+
+    friend Matrix operator*(const Matrix& a, const Matrix& b) {
+        assert(a.m == b.n);
+
+        Matrix c;
+        c.resize(a.n, b.m);
+        for (int i = 0; i < a.n; i++)
+            for (int k = 0; k < b.m; k++) {
+                int64_t ans = 0;
+                for (int j = 0; j < a.m; j++) ans += a.get(i, j) * b.get(j, k);
+                c.mat[i][k] = ans % mod;
+            }
+
+        return c;
+    }
+};
+
+void solve(void) {
+    string n;
+    int m;
+    cin >> n >> m >> mod;
+    reverse(n.begin(), n.end());
+
+    Matrix a, f;
+    a.resize(1, 1 << m), f.resize(1 << m, 1 << m);
+
+    for (int i = 0; i < (1 << m); i++) a[0][i] = 1;
+    for (int S = 0; S < (1 << m); S++)
+        for (int T = 0; T < (1 << m); T++) {
+            f[S][T] = 1;
+            for (int j = 1; j < m; j++)
+                if ((S >> (j - 1) & 1) == (S >> j & 1) && (T >> (j - 1) & 1) == (T >> j & 1) && (S >> j & 1) == (T >> j & 1))
+                    f[S][T] = 0;
+        }
+
+    {
+        int p = 0;
+        while (n[p] == '0') p++;
+        n[p]--;
+        while (p) n[--p] = '9';
+        while (n.back() == '0') n.pop_back();
+    }
+
+    while (!n.empty()) {
+        if ((n.front() - '0') & 1) a = a * f;
+        f = f * f;
+        for (int i = (int)n.size() - 1; ~i; i--) {
+            if (i && (n[i] - '0') & 1) n[i - 1] += 10;
+            n[i] = '0' + ((n[i] - '0') >> 1);
+        }
+        while (n.back() == '0') n.pop_back();
+    }
+
+    int64_t ans = 0;
+    for (int i = 0; i < (1 << m); i++) ans += a.get(0, i);
+    cout << ans % mod << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+#ifndef LOCAL
+    freopen("nice.in", "r", stdin), freopen("nice.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;
+}