Precreation contest files

Codeforces/CodeforcesRound1016(Div3)/DSkibidiTable/input1

@@ -0,0 +1,18 @@
+2
+2
+5
+-> 4 3
+<- 15
+<- 4
+-> 3 1
+-> 1 3
+1
+8
+-> 1 1
+-> 1 2
+-> 2 1
+-> 2 2
+<- 1
+<- 2
+<- 3
+<- 4

Codeforces/CodeforcesRound1016(Div3)/DSkibidiTable/output1

@@ -0,0 +1,13 @@
+7
+2 3
+1 2
+9
+13
+1
+4
+3
+2
+1 1
+2 2
+2 1
+1 2

Codeforces/CodeforcesRound1016(Div3)/DSkibidiTable/solution.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+
+using namespace std;
+
+struct {
+
+}
+
+
+void solve() {
+  int q;
+  cin >> q;
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/CodeforcesRound1034(Div3)/ABlackboardGame/input1

@@ -0,0 +1,6 @@
+5
+2
+4
+5
+7
+100

Codeforces/CodeforcesRound1034(Div3)/ABlackboardGame/output1

@@ -0,0 +1,5 @@
+Alice
+Bob
+Alice
+Alice
+Bob

Codeforces/CodeforcesRound1034(Div3)/ABlackboardGame/solution.cpp

@@ -0,0 +1,16 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--) {
+    int n;
+    cin >> n;
+    if (!(n & ((1 << 2) - 1)))
+      cout << "Bob\n";
+    else
+      cout << "Alice\n";
+  }
+}

Codeforces/CodeforcesRound1034(Div3)/BTournament/input1

@@ -0,0 +1,7 @@
+3
+5 2 3
+3 2 4 4 1
+5 4 1
+5 3 4 5 2
+6 1 1
+1 2 3 4 5 6

Codeforces/CodeforcesRound1034(Div3)/BTournament/output1

@@ -0,0 +1,3 @@
+YES
+YES
+NO

Codeforces/CodeforcesRound1034(Div3)/BTournament/solution.cpp

@@ -0,0 +1,30 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void solve() {
+  int n, j, k;
+  cin >> n >> j >> k;
+  vector<int> a(n);
+  for (auto &i : a)
+    cin >> i;
+
+  if (a[j - 1] == *max_element(a.begin(), a.end())) {
+    cout << "YES\n";
+    return;
+  }
+
+  if (k >= 2)
+    cout << "YES\n";
+  else
+    cout << "NO\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/CodeforcesRound1034(Div3)/CPrefixMinandSuffixMax/input1

@@ -0,0 +1,7 @@
+3
+6
+1 3 5 4 7 2
+4
+13 10 12 20
+7
+1 2 3 4 5 6 7

Codeforces/CodeforcesRound1034(Div3)/CPrefixMinandSuffixMax/output1

@@ -0,0 +1,3 @@
+100011
+1101
+1000001

Codeforces/CodeforcesRound1034(Div3)/CPrefixMinandSuffixMax/solution.cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void min_maxer(vector<int> &_a, vector<int> &pre, vector<int> &stu,
+               vector<bool> &map) {
+  int n = _a.size();
+  map[0] = true;
+  map[n - 1] = true;
+
+  for (int i = 1; i < n; i++) {
+    if (_a[i] < _a[i - 1])
+      map[i] = true;
+    if (_a[n - i - 1] < _a[n - i - 2])
+      map[i] = true;
+  }
+}
+
+void solve() {
+  int n;
+  cin >> n;
+  vector<int> a(n);
+  for (auto &i : a)
+    cin >> i;
+
+  vector<int> min_prefix(n), max_stufix(n);
+  vector<bool> map(n);
+  min_maxer(a, min_prefix, max_stufix, map);
+  for (auto i : map)
+    cout << i;
+  cout << "\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/CodeforcesRound1034(Div3)/EMEXCount/input1

@@ -0,0 +1,11 @@
+5
+5
+1 0 0 1 2
+6
+3 2 0 4 5 1
+6
+1 2 0 1 3 2
+4
+0 3 4 1
+5
+0 0 0 0 0

Codeforces/CodeforcesRound1034(Div3)/EMEXCount/output1

@@ -0,0 +1,5 @@
+1 2 4 3 2 1
+1 6 5 4 3 2 1
+1 3 5 4 3 2 1
+1 3 3 2 1
+1 1 1 1 1 1

Codeforces/CodeforcesRound1034(Div3)/EMEXCount/solution.cpp

@@ -0,0 +1,31 @@
+#include "iostream"
+#include <map>
+
+using namespace std;
+
+void solve() {
+  int n, x;
+  cin >> n;
+  map<int, int> hash_map;
+
+  for (int i = 0; i < n; i++) {
+    cin >> x;
+    if (hash_map.count(x) == 0)
+      hash_map[x] = 1;
+    else
+      hash_map[x]++;
+  }
+
+  for (int k = 0; k <= n; k++) {
+    int cur_mex = 0;
+    for (auto &i : hash_map) {
+    }
+  }
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/CodeforcesRound1035(Div2)/AAddorXOR/input1

@@ -0,0 +1,8 @@
+7
+1 4 1 2
+1 5 2 1
+3 2 2 1
+1 3 2 1
+2 1 1 2
+3 1 1 2
+1 100 10000000 10000000

Codeforces/CodeforcesRound1035(Div2)/AAddorXOR/output1

@@ -0,0 +1,7 @@
+3
+6
+1
+3
+-1
+-1
+990000000

Codeforces/CodeforcesRound1035(Div2)/AAddorXOR/solution.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+
+using namespace std;
+
+void solve() {
+  int a, b, x, y;
+  cin >> a >> b >> x >> y;
+
+  if (a > b) {
+    if (a - b == 1) {
+      if (a % 2 != 0) {
+        cout << y << endl;
+        return;
+      }
+    }
+    cout << "-1\n";
+
+    return;
+  }
+
+  int diff = b - a;
+  int xdiff = diff * x;
+  if (diff % 2 == 0) {
+    cout << min(xdiff, ((diff * x) / 2) + ((diff * y) / 2)) << endl;
+    return;
+  } else {
+    if (a % 2 != 0) {
+
+      cout << min(xdiff, (diff / 2 + 1) * x + (diff / 2) * y) << endl;
+      return;
+    } else {
+      cout << min(xdiff, (diff / 2) * x + (diff / 2 + 1) * y) << endl;
+      return;
+    }
+  }
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/CodeforcesRound1037(Div3)/AOnlyOneDigit/input1

@@ -0,0 +1,6 @@
+5
+6
+96
+78
+122
+696

Codeforces/CodeforcesRound1037(Div3)/AOnlyOneDigit/output1

@@ -0,0 +1,5 @@
+6
+6
+7
+1
+6

Codeforces/CodeforcesRound1037(Div3)/AOnlyOneDigit/solution.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--) {
+    int x;
+    cin >> x;
+    string xstr = to_string(x);
+
+    int res = 10;
+    for (const char &i : xstr) {
+      res = min(res, (int)(i - '0'));
+    }
+    cout << res << endl;
+  }
+}

Codeforces/CodeforcesRound1037(Div3)/BNoCasinointheMountains/input1

@@ -0,0 +1,11 @@
+5
+5 1
+0 1 0 0 0
+7 3
+0 0 0 0 0 0 0
+3 1
+1 1 1
+4 2
+0 1 0 1
+6 2
+0 0 1 0 0 0

Codeforces/CodeforcesRound1037(Div3)/BNoCasinointheMountains/output1

@@ -0,0 +1,5 @@
+3
+2
+0
+0
+2

Codeforces/CodeforcesRound1037(Div3)/BNoCasinointheMountains/solution.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void solve() {
+  int n, k;
+  cin >> n >> k;
+  vector<int> a(n);
+  for (int &i : a)
+    cin >> i;
+
+  int res = 0;
+  int len = 0;
+  for (int i = 0; i < n; i++) {
+    if (len == k) {
+      len = 0;
+      res++;
+      continue;
+    }
+    if (a[i] == 0) {
+      len++;
+    }
+    if (a[i] == 1) {
+      len = 0;
+    }
+  }
+  if (len == k)
+    res++;
+  cout << res << endl;
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/CodeforcesRound1037(Div3)/CIWillDefinitelyMakeIt/input1

@@ -0,0 +1,11 @@
+5
+5 3
+3 2 1 4 5
+3 1
+1 3 4
+4 4
+4 4 4 2
+6 2
+2 3 6 9 1 2
+4 2
+1 2 5 6

Codeforces/CodeforcesRound1037(Div3)/CIWillDefinitelyMakeIt/output1

@@ -0,0 +1,5 @@
+YES
+NO
+YES
+YES
+NO

Codeforces/CodeforcesRound1037(Div3)/CIWillDefinitelyMakeIt/solution.cpp

@@ -0,0 +1,37 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void solve() {
+  int n, k;
+  cin >> n >> k;
+  vector<int> a(n);
+  for (auto &i : a)
+    cin >> i;
+  int h = a[k - 1];
+  sort(a.begin(), a.end());
+
+  int time = 0;
+  for (auto H : a) {
+    if (H <= h)
+      continue;
+    time += H - h;
+    if (time > h) {
+      cout << "NO\n";
+      return;
+    }
+    h = H;
+  }
+
+  cout << "YES\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--) {
+    solve();
+  }
+}

Codeforces/CodeforcesRound1037(Div3)/EGCD,Unlucky!/input1

@@ -0,0 +1,16 @@
+5
+6
+72 24 3 3 3 3
+3 3 3 6 12 144
+3
+1 2 3
+4 5 6
+5
+125 125 125 25 25
+25 25 25 25 75
+4
+123 421 282 251
+125 1981 239 223
+3
+124 521 125
+125 121 121

Codeforces/CodeforcesRound1037(Div3)/EGCD,Unlucky!/output1

@@ -0,0 +1,5 @@
+YES
+NO
+YES
+NO
+NO

Codeforces/CodeforcesRound1037(Div3)/EGCD,Unlucky!/solution.cpp

@@ -0,0 +1,48 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void solve() {
+  int n;
+  cin >> n;
+  vector<int> pre(n), stu(n);
+  for (int &i : pre)
+    cin >> i;
+  for (int &i : stu)
+    cin >> i;
+
+  if (pre[n - 1] != stu[0]) {
+    cout << "NO\n";
+    return;
+  }
+
+  for (int i = 0; i < n - 1; i++) {
+    if (pre[i] < pre[i + 1]) {
+      cout << "NO\n";
+      return;
+    }
+    if (pre[i] % pre[i + 1] != 0) {
+      cout << "NO\n";
+      return;
+    }
+  }
+  for (int i = n - 1; i > 0; i--) {
+    if (stu[i] < stu[i - 1]) {
+      cout << "NO\n";
+      return;
+    }
+    if (stu[i] % stu[i - 1] != 0) {
+      cout << "NO\n";
+      return;
+    }
+  }
+  cout << "YES\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/EPICInstituteofTechnologyRoundSummer2025(CodeforcesRound1036,Div1Div2)/ADerangedDeletions/input1

@@ -0,0 +1,7 @@
+3
+3
+2 2 3
+5
+4 5 5 2 4
+1
+1

Codeforces/EPICInstituteofTechnologyRoundSummer2025(CodeforcesRound1036,Div1Div2)/ADerangedDeletions/output1

@@ -0,0 +1,5 @@
+NO
+YES
+4
+4 5 2 4
+NO

Codeforces/EPICInstituteofTechnologyRoundSummer2025(CodeforcesRound1036,Div1Div2)/ADerangedDeletions/solution.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+void solve() {
+  int n;
+  cin >> n;
+  vector<int> a(n);
+  for (int &i : a)
+    cin >> i;
+
+  for (int i = 0; i < n - 1; i++) {
+    if (a[i] > a[i + 1]) {
+      cout << "YES\n2\n";
+      cout << a[i] << " " << a[i + 1] << "\n";
+      return;
+    }
+  }
+  cout << "NO\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/EPICInstituteofTechnologyRoundSummer2025(CodeforcesRound1036,Div1Div2)/BMinimiseSum/input1

@@ -0,0 +1,7 @@
+3
+2
+1 2
+3
+1 2 3
+4
+3 0 2 3

Codeforces/EPICInstituteofTechnologyRoundSummer2025(CodeforcesRound1036,Div1Div2)/BMinimiseSum/output1

@@ -0,0 +1,3 @@
+2
+2
+3

Codeforces/EPICInstituteofTechnologyRoundSummer2025(CodeforcesRound1036,Div1Div2)/BMinimiseSum/solution.cpp

@@ -0,0 +1,22 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+void solve() {
+  int n;
+  cin >> n;
+  vector<int> a(n);
+  for (auto &i : a)
+    cin >> i;
+
+  cout << min(a[0] + a[1], 2 * a[0]) << "\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--)
+    solve();
+}

Codeforces/EducationalCodeforcesRound177(RatedforDiv2)/ACloudberryJam/input1

@@ -0,0 +1,3 @@
+2
+1
+3

Codeforces/EducationalCodeforcesRound177(RatedforDiv2)/ACloudberryJam/output1

@@ -0,0 +1,2 @@
+2
+6

Codeforces/EducationalCodeforcesRound177(RatedforDiv2)/ACloudberryJam/solution.cpp

@@ -0,0 +1,14 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+  int t;
+  cin >> t;
+
+  while (t--) {
+    int n;
+    cin >> n;
+    cout << 2 * n << '\n';
+  }
+}

Codeforces/GoodBye20242025isNEAR/ATenderCarpenter/input1

@@ -0,0 +1,11 @@
+5
+4
+2 3 5 7
+4
+115 9 2 28
+5
+8 4 1 6 2
+6
+1 5 4 1 4 7
+2
+100000 100000

Codeforces/GoodBye20242025isNEAR/ATenderCarpenter/output1

@@ -0,0 +1,5 @@
+YES
+NO
+NO
+YES
+YES

Codeforces/GoodBye20242025isNEAR/ATenderCarpenter/solution.cpp

@@ -0,0 +1,55 @@
+#include <iostream>
+
+using namespace std;
+
+int a[200];
+
+bool check(int a, int b, int c) {
+  if (a + b <= c)
+    return false;
+  if (a + c <= b)
+    return false;
+  if (b + c <= a)
+    return false;
+  return true;
+}
+
+void run() {
+  int n;
+  cin >> n;
+  for (int i = 0; i < n; i++)
+    cin >> a[i];
+
+  if (n == 2) {
+    if (check(a[0], a[0], a[1]) || check(a[0], a[1], a[1])) {
+      cout << "YES\n";
+    } else {
+      cout << "NO\n";
+    }
+    return;
+  }
+
+  for (int i = 0; i < n - 2; i++) {
+    if (check(a[i], a[i + 1], a[i + 2])) {
+      cout << "YES\n";
+      return;
+    }
+  }
+
+  for (int i = 0; i < n - 1; i++) {
+    if (check(a[i], a[i], a[i + 1]) || check(a[i], a[i + 1], a[i + 1])) {
+      cout << "YES\n";
+      return;
+    }
+  }
+
+  cout << "NO\n";
+}
+
+int main() {
+  int t;
+  cin >> t;
+  while (t--) {
+    run();
+  };
+}

misc/bdhsg_1015/max3.cpp

@@ -0,0 +1,21 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("max3.inp", "r", stdin);
+
+  int n;
+  cin >> n;
+  vector<int> a(n);
+  for (int &i : a)
+    cin >> i;
+
+  int res = 0;
+  for (int i = 0; i < n - 2; i++)
+    res = max(res, a[i] + a[i + 1] + a[i + 2]);
+
+  cout << res << '\n';
+}

misc/bdhsg_1015/max3.inp

@@ -0,0 +1,2 @@
+6
+1 3 4 2 7 9

misc/bdhsg_1015/search.cpp

@@ -0,0 +1,32 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("search.inp", "r", stdin);
+
+  int n, x;
+  cin >> n >> x;
+  vector<int> a(n);
+  for (int &i : a)
+    cin >> i;
+
+  if (x - 1 > n || x < 0) {
+    cout << -1 << '\n';
+    return 0;
+  } else {
+    x = a[x - 1];
+  }
+  int cnt = 0;
+  for (int i = 0; i < n; i++) {
+    // cout << a[i] << '\n';
+    if (a[i] == x) {
+      cout << i + 1 << ' ';
+      cnt++;
+    }
+  }
+  cout << '\n';
+  cout << ((cnt == 0) ? -1 : cnt) << '\n';
+}

misc/bdhsg_1015/search.inp

@@ -0,0 +1,2 @@
+6 2
+1 3 3 5 7 3

misc/binary-search/ghepcap.cpp

@@ -0,0 +1,35 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int a[100000];
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("ghepcap.inp", "r", stdin);
+
+  int n;
+  cin >> n;
+  for (int i = 0; i < n; i++)
+    cin >> a[i];
+  sort(a, a + n);
+  // 89 90 91 99 100 101
+  int res = 0;
+  for (int j = 0; j < n; j++) {
+    int l = 0, r = j;
+    // int ans = a[n - 1];
+    while (l < r) {
+      int mid = (l + r) / 2;
+      if (10 * a[mid] < a[j] * 9) {
+        l = mid + 1;
+      } else {
+        r = mid;
+        // ans = min(ans, mid);
+      }
+    }
+    // res += j - ans;
+    res += j - l;
+  }
+  cout << res << '\n';
+}

misc/binary-search/ghepcap.inp

@@ -0,0 +1,4 @@
+6
+100 89 90 101 91 99
+
+

misc/binary-search/p145sumg.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+#include <ios>
+using namespace std;
+
+int a[100000];
+int n, m;
+
+int checker(int k) {
+  int ret = 0;
+  for (int i = 0; i < n; i++) {
+    ret += k / a[i];
+  }
+  return ret;
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("p145sumg.inp", "r", stdin);
+
+  cin >> n >> m;
+  int l = 1, r;
+  for (int i = 0; i < n; i++) {
+    cin >> a[i];
+    r = max(r, a[i]);
+  }
+  r *= m;
+
+  int res = r;
+  while (l < r) {
+    int mid = (l + r) / 2;
+    if (checker(mid) >= m) {
+      r = mid;
+      res = min(mid, res);
+    } else {
+      l = mid + 1;
+    }
+  }
+  cout << res << "\n";
+}

misc/binary-search/p145sumg.inp

@@ -0,0 +1,8 @@
+7 10
+3
+8
+3
+6
+9
+2
+4

misc/binary-search/ptit126j.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+int a[1000000];
+int n, m;
+
+int check(int k) {
+  int res = 0;
+  for (int i = 0; i < n; i++) {
+    if (a[i] - k > 0)
+      res += a[i] - k;
+  }
+  return res;
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+
+  freopen("ptit126j.inp", "r", stdin);
+
+  cin >> n >> m;
+  for (int i = 0; i < n; i++)
+    cin >> a[i];
+  sort(a, a + n);
+
+  // 10 15 17 20
+  int l = 0, r = a[n - 1];
+  int res = a[n - 1];
+  while (l < r) {
+    int mid = (l + r) / 2;
+
+    if (check(mid) >= m) {
+      // cout << mid << "\n";
+      res = mid;
+      l = mid + 1;
+    } else {
+      r = mid;
+    }
+  }
+  cout << res << '\n';
+}

misc/binary-search/ptit126j.inp

@@ -0,0 +1,2 @@
+5 20
+4 42 40 26 46

misc/binary-search/toy.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m;
+
+int checker(const vector<int> &_a, int k) {
+  int _n = n;
+  for (auto i : _a) {
+    while (i > k) {
+      i -= k;
+      _n -= k;
+    }
+    if (i > 0) {
+      _n - k
+    }
+  }
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("toy.inp", "r", stdin);
+
+  cin >> n >> m;
+  vector<int> a(n);
+  for (auto &i : a)
+    cin >> i;
+
+  int l = 0, r = n;
+  while (l < r) {
+    int mid = (l + r) / 2;
+
+    if (checker(a, mid)) {
+      r = mid;
+    } else {
+      l = mid + 1;
+    }
+  }
+}

misc/binary-search/toy.inp

@@ -0,0 +1,3 @@
+5 2
+4
+7

misc/chuyen-de-xau/B3.INP

@@ -0,0 +1,6 @@
+5
+ABCD
+EFGHIJK
+TINHOCTRE
+ABCD
+EFGHIJK

misc/chuyen-de-xau/B4.INP

@@ -0,0 +1,4 @@
+3
+34
+3
+30

misc/chuyen-de-xau/B6.INP

@@ -0,0 +1,3 @@
+3 11
+3 4 2
+123 0 45

misc/chuyen-de-xau/b2.cpp

@@ -0,0 +1,45 @@
+#include <iostream>
+
+using namespace std;
+
+int segn[300];
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+
+  for (int j = 0; j < 300; j++)
+    segn[j] = 0;
+  string S;
+  cin >> S;
+  const int n = S.length();
+  int res1 = 0;
+  int res2 = 0;
+
+  int l = 0, r = 1;
+  int i = 0;
+  while (r < n) {
+    if (S[l] == S[r])
+      r++;
+    else {
+      segn[i] = r - l;
+      l = r;
+      r++;
+      i++;
+    }
+  }
+  segn[i] = r - l;
+  i++;
+
+  for (int k = 0; k < i; k++) {
+    res1 = max(res1, segn[k]);
+    if (segn[k + 1] == 1) {
+      res2 = max(res2, segn[k] + segn[k + 1] + segn[k + 2]);
+    }
+    if (k != 0 || k != n - 1) {
+      res2 = max(res2, segn[k] + 1);
+    }
+  }
+  cout << res1 << '\n';
+  cout << res2 << '\n';
+}

misc/chuyen-de-xau/b3.cpp

@@ -0,0 +1,28 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("B3.INP", "r", stdin);
+
+  map<string, char> hash;
+
+  int q;
+  cin >> q;
+  for (int i = 0; i < q; i++) {
+    string a;
+    cin >> a;
+    // cout << a;
+    if (hash.find(a) == hash.end()) {
+      hash[a] = 1;
+    } else {
+      hash[a] = 0;
+    }
+  }
+
+  for (const auto i : hash) {
+    if (i.second == 1)
+      cout << i.first << '\n';
+  }
+}

misc/chuyen-de-xau/b4.cpp

@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+string S[100];
+
+bool check(const string &a, const string &b) {
+  const string ab = a + b, ba = b + a;
+  if (stoi(ab) < stoi(ba))
+    return false;
+  return true;
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  freopen("B4.INP", "r", stdin);
+
+  int n;
+  cin >> n;
+  for (int i = 0; i < n; i++) {
+    string a;
+    cin >> a;
+    S[i] = a;
+  }
+
+  sort(S, S + n, check);
+  for (int i = 0; i < n; i++) {
+    cout << S[i];
+  }
+  cout << '\n';
+}

misc/chuyen-de-xau/b5.cpp

@@ -0,0 +1,38 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  string s;
+  cin >> s;
+
+  vector<char> digits;
+  for (char c : s) {
+    if (isdigit(c))
+      digits.push_back(c);
+  }
+
+  int m = digits.size();
+  string result = "";
+  int pos = 0;
+
+  for (int need = 5; need > 0; need--) {
+    char best = '0';
+    int bestPos = pos;
+
+    for (int i = pos; i <= m - need; i++) {
+      if (digits[i] > best) {
+        best = digits[i];
+        bestPos = i;
+      }
+    }
+
+    result.push_back(best);
+    pos = bestPos + 1;
+  }
+
+  cout << result;
+  return 0;
+}

misc/chuyen-de-xau/b6.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+
+  int p, k;
+  cin >> p >> k;
+  vector<int> a(p), s(p);
+  for (int &i : a)
+    cin >> i;
+  for (int &i : s)
+    cin >> i;
+
+  deque<int> stack;
+
+  for (int i = 0; i < p; i++) {
+    while (a[i]--) {
+    }
+  }
+}

misc/chuyen-de-xau/b7.cpp

@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+int counter[(int)('z' - 'a')];
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+
+  string a;
+  cin >> a;
+  for (const auto i : a) {
+    counter[i - 'a']++;
+  }
+
+  int sum = 0;
+  for (const auto i : counter) {
+    sum += i;
+  }
+
+  int max_x = 0;
+  char max_c;
+  for (int i = 0; i < 'z' - 'a'; i++) {
+    if (counter[i] > max_x) {
+      max_x = counter[i];
+      max_c = 'a' + i;
+    }
+  }
+  cout << sum << ' ' << max_c << '\n';
+}

misc/chuyen-de-xau/b8.cpp

@@ -0,0 +1,22 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+string words[20];
+
+bool checker(const string &a, const string &b) { return a.size() < b.size(); }
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(nullptr);
+  freopen("b8.inp", "r", stdin);
+
+  int n = 0;
+  while (cin >> words[n] && n < 20)
+    n++;
+
+  stable_sort(words, words + n, checker);
+  for (int i = 0; i < n; i++) {
+    cout << words[i] << " ";
+  }
+  cout << '\n';
+}

misc/chuyen-de-xau/b8.inp

@@ -0,0 +1 @@
+acb abcde abcd abc

misc/hsg-hn-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-hn-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-hn-2025/denlong.cpp

@@ -0,0 +1,17 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+  int n, k, x;
+  cin >> n >> k >> x;
+  vector<vector<int>> hash(9, vector<int>(n, 0));
+
+  for (int i = 0; i < n; i++) {
+    int a;
+    cin >> a;
+    if (i == 0)
+      hash[a][i] = 1;
+    else
+      hash[a][i] = hash[a][i - 1] + 1;
+  }
+}

misc/hsg-hn-2025/denlong.inp

@@ -0,0 +1,2 @@
+6 2 2
+1 9 3 2 3 5

misc/hsg-hn-2025/muasam.cpp

@@ -0,0 +1,35 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const int MAX_N = 1e6;
+int a[MAX_N];
+
+int main() {
+  freopen("muasam.inp", "r", stdin);
+  freopen("muasam.out", "w", stdout);
+
+  ios::sync_with_stdio(false);
+  cin.tie(nullptr);
+
+  int n, l, r;
+  cin >> n >> l >> r;
+  for (int i = 0; i < n; i++)
+    cin >> a[i];
+  int res = 1e9;
+
+  sort(a, a + n);
+  int L = 0, R = n - 1;
+  while (L < R) {
+    int sum = a[L] + a[R];
+    if (sum > r)
+      R--;
+    else if (sum < l)
+      L++;
+    else {
+      res = min(res, sum);
+      R--;
+    }
+  }
+  cout << res << '\n';
+}

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();
+}