Codeforces: Codeforces Round 1022 (Div. 2)

Macesuted · Macesuted · commit a9790765d8c9 · 2025-05-07T22:25:10.000+08:00
diff --git a/Codeforces/2108A.cpp b/Codeforces/2108A.cpp
@@ -0,0 +1,44 @@
+/**
+ * @file 2108A.cpp
+ * @author Macesuted (i@macesuted.moe)
+ * @date 2025-05-07
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+void solve(void) {
+    int n;
+    cin >> n;
+    int64_t sum = 0;
+    for (int i = 1; i <= n; i++) sum += abs((n - i + 1) - i);
+    cout << 1 + sum / 2 << endl;
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}
diff --git a/Codeforces/2108B.cpp b/Codeforces/2108B.cpp
@@ -0,0 +1,53 @@
+/**
+ * @file 2108B.cpp
+ * @author Macesuted (i@macesuted.moe)
+ * @date 2025-05-07
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+void solve(void) {
+    int n, x;
+    cin >> n >> x;
+    if (x == 0) {
+        if (n == 1) return cout << -1 << endl, void();
+        if (n % 2 == 0) return cout << n << endl, void();
+        return cout << n + 3 << endl, void();
+    }
+    if (x == 1) {
+        if (n % 2 == 0) return cout << n + 3 << endl, void();
+        return cout << n << endl, void();
+    }
+    int b = min(n, __builtin_popcount(x));
+    if (b > 1 && (n - b) % 2 == 1) b--;
+    cout << n - b + x + ((n - b) % 2 == 1) << endl;
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}
diff --git a/Codeforces/2108C.cpp b/Codeforces/2108C.cpp
@@ -0,0 +1,76 @@
+/**
+ * @file 2108C.cpp
+ * @author Macesuted (i@macesuted.moe)
+ * @date 2025-05-07
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 200005
+
+int a[maxn], fa[maxn], id[maxn];
+bool mark[maxn];
+
+int getfa(int p) { return fa[p] == p ? p : fa[p] = getfa(fa[p]); }
+
+void merge(int x, int y) {
+    x = getfa(x), y = getfa(y);
+    if (x != y) fa[x] = y, mark[y] |= mark[x];
+    return;
+}
+
+void solve(void) {
+    int n;
+    cin >> n;
+    for (int i = 1; i <= n; i++) cin >> a[i], id[i] = fa[i] = i, mark[i] = false;
+    sort(id + 1, id + n + 1, [&](int x, int y) { return a[x] > a[y]; });
+
+    int ans = 0;
+    for (int l = 1, r; l <= n; l = r + 1) {
+        r = l;
+        while (r + 1 <= n && a[id[r + 1]] == a[id[l]]) r++;
+
+        for (int i = l; i <= r; i++) {
+            int p = id[i];
+            if (1 < p && a[p - 1] >= a[p]) merge(p - 1, p);
+            if (p < n && a[p] <= a[p + 1]) merge(p, p + 1);
+        }
+
+        for (int i = l; i <= r; i++) {
+            int p = getfa(id[i]);
+            if (!mark[p]) mark[p] = true, ans++;
+        }
+    }
+
+    cout << ans << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}
diff --git a/Codeforces/2108D.cpp b/Codeforces/2108D.cpp
@@ -0,0 +1,67 @@
+/**
+ * @file 2108D.cpp
+ * @author Macesuted (i@macesuted.moe)
+ * @date 2025-05-07
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+bool mem1;
+
+int query(int p) {
+    cout << "? " << p << endl;
+    int x;
+    cin >> x;
+    return x;
+}
+
+void solve(void) {
+    int n, k;
+    cin >> n >> k;
+
+    if (n == 2 * k) return cout << "! " << k << ' ' << k << endl, void();
+
+    int xl = k, xr = n - k + 1;
+    for (int i = 1; i <= k && xl + 1 < xr; i++) {
+        int l = xl / k, r = xr / k - 1;
+        while (i + l * k > xl) l--;
+        while (i + r * k < xr) r++;
+
+        int v = query(i + l * k);
+        if (query(i + r * k) == v) continue;
+
+        while (l + 1 < r) {
+            int m = (l + r) >> 1;
+            (query(i + m * k) == v ? l : r) = m;
+        }
+        xl = max(xl, i + l * k), xr = min(xr, i + r * k);
+    }
+
+    if (xl + 1 != xr) return cout << "! -1" << endl, void();
+
+    cout << "! " << xl << ' ' << n - xr + 1 << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}
diff --git a/Codeforces/2108E.cpp b/Codeforces/2108E.cpp
@@ -0,0 +1,89 @@
+/**
+ * @file 2108E.cpp
+ * @author Macesuted (i@macesuted.moe)
+ * @date 2025-05-07
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 200005
+
+using pii = pair<int, int>;
+
+vector<vector<int>> graph;
+int col[maxn], fa[maxn], dep[maxn], siz[maxn], dfn[maxn], id[maxn];
+int n;
+
+int dfnt;
+void dfs(int p) {
+    id[dfn[p] = ++dfnt] = p, siz[p] = 1;
+    for (auto q : graph[p]) {
+        if (q == fa[p]) continue;
+        fa[q] = p, dep[q] = dep[p] + 1;
+        dfs(q);
+        siz[p] += siz[q];
+    }
+    return;
+}
+int getRoot(int p) {
+    for (auto q : graph[p])
+        if (q != fa[p] && 2 * siz[q] > n) return getRoot(q);
+    return p;
+}
+
+void solve(void) {
+    cin >> n;
+
+    graph.clear(), graph.resize(n + 1);
+    for (int i = 1, x, y; i < n; i++) cin >> x >> y, graph[x].push_back(y), graph[y].push_back(x);
+
+    fa[1] = -1, dep[1] = 0, dfnt = 0, dfs(1);
+    int root = getRoot(1);
+    fa[root] = -1, dep[root] = 0, dfnt = 0, dfs(root);
+
+    int x = -1;
+    for (int i = 1; i <= n; i++)
+        if (i != root && (x == -1 || siz[i] + dep[i] < siz[x] + dep[x])) x = i;
+
+    cout << x << ' ' << fa[x] << endl;
+
+    for (int i = 1; i <= n; i++) col[i] = 0;
+    vector<int> nodes;
+    for (int i = 1; i <= n; i++)
+        if (id[i] != x) nodes.push_back(id[i]);
+    for (int i = 0, j = nodes.size() / 2; j < (int)nodes.size(); i++, j++) col[nodes[i]] = col[nodes[j]] = i + 1;
+    if (x < fa[x]) swap(col[x], col[fa[x]]);
+
+    for (int i = 1; i <= n; i++) cout << col[i] << ' ';
+    cout << endl;
+
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}
diff --git a/Codeforces/2108F.cpp b/Codeforces/2108F.cpp
