Codeforces: Educational Codeforces Round 178 (Rated for Div. 2)

Author: Macesuted

Codeforces/2104A.cpp

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+/**
+ * @file 2104A.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-04-28
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+void solve(void) {
+    int a, b, c;
+    cin >> a >> b >> c;
+    cout << (((a + b + c) % 3 == 0 && c - b >= b - a) ? "YES" : "NO") << 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;
+}

Codeforces/2104B.cpp

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+/**
+ * @file 2104B.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-04-28
+ *
+ * @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], mv[maxn];
+
+void solve(void) {
+    int n;
+    cin >> n;
+    for (int i = 1; i <= n; i++) cin >> a[i], mv[i] = max(mv[i - 1], a[i]);
+    int64_t sum = 0;
+    for (int i = n; i; i--) {
+        sum += a[i];
+        cout << sum + max(0, mv[i - 1] - a[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;
+}

Codeforces/2104C.cpp

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+/**
+ * @file 2104C.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-04-28
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+void solve(void) {
+    int n;
+    string s;
+    cin >> n >> s, s = ' ' + s;
+    if (s[n] == 'A') {
+        if (s[1] == 'A' || s[n - 1] == 'A')
+            cout << "Alice" << endl;
+        else
+            cout << "Bob" << endl;
+    } else {
+        for (int i = 1; i < n; i++)
+            if (s[i] == 'B') return cout << "Bob" << endl, void();
+        cout << "Alice" << 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;
+}

Codeforces/2104D.cpp

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+/**
+ * @file 2104D.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-04-28
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxv 8000005
+#define maxn 400005
+
+bool notp[maxv];
+vector<int> prime;
+int64_t sum[maxn];
+int a[maxn];
+
+void solve(void) {
+    int n;
+    cin >> n;
+    int64_t tot = 0;
+    for (int i = 1; i <= n; i++) cin >> a[i], tot += a[i];
+    sort(a + 1, a + n + 1);
+    int ans = 0;
+    while (ans < n - 1 && tot < sum[n - ans]) tot -= a[++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
+
+    for (int i = 2; i < maxv; i++) {
+        if (!notp[i]) prime.push_back(i);
+        for (auto j = prime.begin(); i * *j < maxv; j++) {
+            notp[i * *j] = true;
+            if (i % *j == 0) break;
+        }
+    }
+
+    for (int i = 1; i < maxn; i++) sum[i] = sum[i - 1] + prime[i - 1];
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}

Codeforces/2104E.cpp

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+/**
+ * @file 2104E.cpp
+ * @author Macesuted ([email protected])
+ * @date 2025-04-28
+ *
+ * @copyright Copyright (c) 2025
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 1000005
+
+int nxt[maxn][26], f[maxn];
+
+void solve(void) {
+    int n, k;
+    cin >> n >> k;
+    string s;
+    cin >> s, s = ' ' + s;
+
+    f[n + 1] = 0;
+    f[n] = 1;
+    for (int i = 0; i < k; i++) nxt[n][i] = nxt[n + 1][i] = n + 1;
+    for (int i = n - 1; ~i; i--) {
+        for (int j = 0; j < k; j++) nxt[i][j] = nxt[i + 1][j];
+        nxt[i][s[i + 1] - 'a'] = i + 1;
+
+        f[i] = INT_MAX;
+        for (int j = 0; j < k; j++) f[i] = min(f[i], f[nxt[i][j]] + 1);
+    }
+
+    int q;
+    cin >> q;
+    while (q--) {
+        string t;
+        cin >> t;
+        int p = 0;
+        for (char c : t) p = nxt[p][c - 'a'];
+        cout << f[p] << 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;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}