Precreation contest files

misc/hsg-hp-2025/.vscode/launch.json

@@ -0,0 +1,22 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Debug C++ (input.inp)",
+      "type": "cppdbg",
+      "request": "launch",
+      "program": "${workspaceFolder}/${fileBasenameNoExtension}",
+      "args": ["<", "${fileBasenameNoExtension}.inp"],
+      "cwd": "${workspaceFolder}",
+      "preLaunchTask": "Build C++",
+      "MIMode": "gdb",
+      "externalConsole": false,
+      "setupCommands": [
+        {
+          "description": "Enable pretty printing",
+          "text": "-enable-pretty-printing"
+        }
+      ]
+    }
+  ]
+}

misc/hsg-hp-2025/.vscode/tasks.json

@@ -0,0 +1,22 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "Build C++",
+      "type": "shell",
+      "command": "g++",
+      "args": [
+        "-std=gnu++17",
+        "-O2",
+        "-g",
+        "${file}",
+        "-o",
+        "${fileBasenameNoExtension}"
+      ],
+      "group": {
+        "kind": "build",
+        "isDefault": true
+      }
+    }
+  ]
+}

misc/hsg-hp-2025/cbai1.cpp

@@ -0,0 +1,24 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+  string a;
+  cin >> a;
+
+  int res = 0;
+  string output = "";
+
+  for (int i = a.length() - 1; i >= 0; i--) {
+    if ('0' <= a[i] && a[i] <= '9')
+      res += (int)(a[i] - '0');
+    else
+      output += a[i];
+  }
+
+  cout << res << '\n';
+  if (output == "")
+    cout << -1 << '\n';
+  else
+    cout << output << '\n';
+}

misc/hsg-hp-2025/cbai2.cpp

@@ -0,0 +1,50 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const int max_n = 1e7;
+
+char is_prime[max_n + 1];
+void sieve() {
+  for (int i = 0; i <= max_n; i++)
+    is_prime[i] = 1;
+  is_prime[0] = 0;
+  is_prime[1] = 0;
+
+  // 2 check
+  for (int i = 4; i <= max_n; i += 2)
+    is_prime[i] = 0;
+
+  // other
+  for (int i = 3; i * i <= max_n; i += 2)
+    if (is_prime[i])
+      for (int j = i * i; j <= max_n; j += i)
+        is_prime[j] = 0;
+}
+
+int solve() {
+  int n;
+  cin >> n;
+  if (!is_prime[n])
+    return 0;
+
+  int digit_sum = 0;
+  while (n) {
+    digit_sum += n % 10;
+    n /= 10;
+  }
+  if (!is_prime[digit_sum])
+    return 0;
+  return 1;
+}
+
+int main() {
+  sieve();
+  int q;
+  cin >> q;
+  int res = 0;
+  while (q--) {
+    res += solve();
+  }
+  cout << res << "\n";
+}

misc/hsg-hp-2025/cbai2.inp

@@ -0,0 +1,2 @@
+6
+2 3 19 23 29 17

misc/hsg-hp-2025/cbai3.cpp

@@ -0,0 +1,28 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+int a[1000000];
+
+int main() {
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  int m, n, S;
+  cin >> m >> n >> S;
+  for (int i = 0; i < m * n; i++)
+    cin >> a[i];
+
+  sort(a, a + m * n);
+
+  int l = 0, r = m * n - 1;
+  int cur_max = -1;
+  while (l < r) {
+    if (a[l] + a[r] > S)
+      r--;
+    else {
+      cur_max = max(cur_max, a[l] + a[r]);
+      l++;
+    }
+  }
+  cout << cur_max << '\n';
+}

misc/hsg-hp-2025/cbai3.inp

@@ -0,0 +1,4 @@
+3 4 10
+6 7 8 9
+5 6 7 8
+9 8 8 7

misc/hsg-hp-2025/cbai4.cpp

@@ -0,0 +1,56 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+void solve() {
+  vector<deque<int>> char_pos(26);
+
+  int n, q;
+  string S;
+  cin >> n >> q >> S;
+
+  vector<int> is_exist(n, 1);
+  set<int> exist_char;
+
+  // O(n)
+  for (int i = 0; i < n; i++) {
+    char_pos[S[i] - 'A'].push_back(i);
+  }
+
+  // O(1)
+  for (int i = 0; i < 26; i++)
+    if (!char_pos[i].empty())
+      exist_char.insert(i);
+
+  while (q--) {
+    if (exist_char.empty())
+      break;
+
+    int t;
+    cin >> t;
+    int target_char;
+    if (t == 0)
+      target_char = *exist_char.begin();
+    else
+      target_char = *exist_char.rbegin();
+
+    int target_idx = char_pos[target_char].front();
+    char_pos[target_char].pop_front();
+    is_exist[target_idx] = 0;
+
+    if (char_pos[target_char].empty())
+      exist_char.erase(target_char);
+  }
+
+  for (int i = 0; i < n; i++)
+    if (is_exist[i])
+      cout << S[i];
+  cout << '\n';
+}
+
+int main() {
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  solve();
+}

misc/hsg-hp-2025/cbai4.inp

@@ -0,0 +1,3 @@
+10 4
+ADBAACDABC
+0 1 1 0