Solved 3 problems in the last Div3

39 files changed, 968 insertions, 0 deletions

diff --git a/codeforces/HalloumiBoxes/main.rs b/codeforces/HalloumiBoxes/main.rs
new file mode 100644
index 0000000..cbc73cd
--- /dev/null
+++ b/codeforces/HalloumiBoxes/main.rs
@@ -0,0 +1,32 @@
+#[allow(dead_code)]
+fn read<T: std::str::FromStr>() -> T {
+    let mut s = String::new();
+    std::io::stdin().read_line(&mut s).ok();
+    s.trim().parse().ok().unwrap()
+}
+
+#[allow(dead_code)]
+fn read_vec<T: std::str::FromStr>() -> Vec<T> {
+    read::<String>()
+        .split_whitespace()
+        .map(|e| e.parse().ok().unwrap())
+        .collect()
+}
+
+#[allow(dead_code)]
+fn read_mat<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
+    (0..n).map(|_| read_vec()).collect()
+}
+
+fn solve() {
+    let (k, n) = (read::<usize>(), read::<usize>());
+    let mut v = read_vec::<usize>();
+}
+
+fn main() {
+    let mut tt = read::<u64>();
+    while tt > 0 {
+        solve();
+        tt -= 1;
+    }
+}
diff --git a/codeforces/HalloumiBoxes/rust-project.json b/codeforces/HalloumiBoxes/rust-project.json
new file mode 100644
index 0000000..a195582
--- /dev/null
+++ b/codeforces/HalloumiBoxes/rust-project.json
@@ -0,0 +1,11 @@
+{
+  "sysroot": "/home/omar/.rustup/toolchains/stable-x86_64-unknown-linux-gnu",
+  "sysroot_src": "/home/omar/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/",
+  "crates": [
+    {
+      "root_module": "main.rs",
+      "edition": "2021",
+      "deps": []
+    }
+  ]
+}
diff --git a/codeforces/MovingChips/main.cpp b/codeforces/MovingChips/main.cpp
new file mode 100755
index 0000000..f847d53
--- /dev/null
+++ b/codeforces/MovingChips/main.cpp
@@ -0,0 +1,104 @@
+#include <algorithm>
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+bool isChip(vi v) {
+  v.resize(unique(all(v)) - v.begin());
+  int n = v.size();
+  if (n == 2) {
+    return true;
+  } else if (n == 1 && v[0] == 1) {
+    return true;
+  } else if (n == 3 && v[0] == 0 && v[1] == 1 && v[2] == 0) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
+int rfind(vi &v) {
+  int n = v.size();
+  for (int i = n - 1; i >= 0; --i) {
+    if (v[i] == 1) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+int helper(vi &v, int idx) {
+  int n = v.size();
+  for (int i = idx; i >= 0; --i) {
+    if (v[i] == 0) {
+      return i;
+    }
+  }
+  return -1;
+}
+
+void solve() {
+  int n;
+  cin >> n;
+  vi v(n);
+  for (auto &x : v) {
+    cin >> x;
+  }
+  int cnt = 0;
+  while (!isChip(v)) {
+    auto last_one = rfind(v);
+    auto first_zero_before_last_one = helper(v, last_one);
+    swap(v[last_one], v[first_zero_before_last_one]);
+    cnt++;
+  }
+  cout << cnt << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/codeforces/MovingChips/main_input0.txt b/codeforces/MovingChips/main_input0.txt
new file mode 100644
index 0000000..5945cde
--- /dev/null
+++ b/codeforces/MovingChips/main_input0.txt
@@ -0,0 +1,11 @@
+5
+8
+0 1 1 1 0 1 1 0
+6
+0 1 0 0 0 0
+6
+1 1 1 1 1 1
+5
+1 0 1 0 1
+9
+0 1 1 0 0 0 1 1 0
diff --git a/codeforces/MovingChips/main_output0.txt b/codeforces/MovingChips/main_output0.txt
new file mode 100644
index 0000000..dff77c1
--- /dev/null
+++ b/codeforces/MovingChips/main_output0.txt
@@ -0,0 +1,5 @@
+1
+0
+0
+2
+3
diff --git a/codeforces/TurtleMath/main.cpp b/codeforces/TurtleMath/main.cpp
new file mode 100755
index 0000000..c602443
--- /dev/null
+++ b/codeforces/TurtleMath/main.cpp
@@ -0,0 +1,82 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+set<int> st1;
+
+void solve() {
+  int n;
+  cin >> n;
+  vector<int> v(n);
+  long long sum = 0;
+  for (auto &x : v) {
+    cin >> x;
+    sum += x;
+  }
+  if (sum % 3 == 0) {
+    cout << 0 << '\n';
+    return;
+  } else {
+    if (sum % 3 == 1) {
+      for (int i = 0; i < n; ++i) {
+        if (st1.count(v[i])) {
+          cout << 1 << '\n';
+          return;
+        }
+      }
+    }
+  }
+  cout << 3 - (sum % 3) << '\n';
+}
+
+int main() {
+  for (int i = 0; i < 1e5; i++) {
+    st1.insert(1 + i * 3);
+  }
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round928/A/main.cpp b/contests/Round928/A/main.cpp
new file mode 100755
index 0000000..539fdb0
--- /dev/null
+++ b/contests/Round928/A/main.cpp
@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() { <()> }
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round928/B/main.cpp b/contests/Round928/B/main.cpp
new file mode 100755
index 0000000..539fdb0
--- /dev/null
+++ b/contests/Round928/B/main.cpp
@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() { <()> }
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round928/C/main.cpp b/contests/Round928/C/main.cpp
new file mode 100755
index 0000000..539fdb0
--- /dev/null
+++ b/contests/Round928/C/main.cpp
@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() { <()> }
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round928/D/main.cpp b/contests/Round928/D/main.cpp
new file mode 100755
index 0000000..05b3cc4
--- /dev/null
+++ b/contests/Round928/D/main.cpp
@@ -0,0 +1,106 @@
+#include <algorithm>
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+int binarySearch(const std::vector<int> &arr, int target) {
+  int left = 0;
+  int right = arr.size() - 1;
+
+  while (left <= right) {
+    int mid = left + (right - left) / 2;
+
+    if (arr[mid] == target) {
+      return mid;
+    } else if (arr[mid] < target) {
+      left = mid + 1;
+    } else {
+      right = mid - 1;
+    }
+  }
+
+  return -1;
+}
+
+int negateNumber(int num) {
+  int signMask = 1 << (sizeof(int) * 8 - 1);
+
+  int inverted = ~num & (signMask - 1);
+
+  return inverted + 1;
+}
+
+void solve() {
+  random_device rd;
+  mt19937 gen(rd());
+  uniform_int_distribution<> distribution(1, INT_MAX);
+  int n;
+  cin >> n;
+  vi v(n);
+  for (auto &x : v) {
+    cin >> x;
+  }
+  sort(all(v));
+  int ans = 0;
+  vector<bool> marked(n, false);
+  for (int i = 0; i < n; i++) {
+    auto it = binarySearch(v, negateNumber(v[i]) - 1);
+    if (it != -1) {
+      ans++;
+      v[it] = distribution(gen);
+      marked[i] = true;
+      marked[it] = true;
+    }
+  }
+  int cnt = count(all(marked), false);
+  cout << ans + cnt << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round928/D/main_input0.txt b/contests/Round928/D/main_input0.txt
new file mode 100644
index 0000000..b9e8c65
--- /dev/null
+++ b/contests/Round928/D/main_input0.txt
@@ -0,0 +1,19 @@
+9
+4
+1 4 3 4
+2
+0 2147483647
+5
+476319172 261956880 2136179468 1671164475 1885526767
+3
+1335890506 811593141 1128223362
+4
+688873446 627404104 1520079543 1458610201
+4
+61545621 2085938026 1269342732 1430258575
+4
+0 0 2147483647 2147483647
+3
+0 0 2147483647
+8
+1858058912 289424735 1858058912 2024818580 1858058912 289424735 122665067 289424735
diff --git a/contests/Round928/D/main_output0.txt b/contests/Round928/D/main_output0.txt
new file mode 100644
index 0000000..6572dc5
--- /dev/null
+++ b/contests/Round928/D/main_output0.txt
@@ -0,0 +1,9 @@
+4
+1
+3
+2
+2
+3
+2
+2
+4
diff --git a/contests/Round928/E/main.cpp b/contests/Round928/E/main.cpp
new file mode 100755
index 0000000..539fdb0
--- /dev/null
+++ b/contests/Round928/E/main.cpp
@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() { <()> }
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round928/F/main.cpp b/contests/Round928/F/main.cpp
new file mode 100755
index 0000000..539fdb0
--- /dev/null
+++ b/contests/Round928/F/main.cpp
@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() { <()> }
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round933/A/main.cpp b/contests/Round933/A/main.cpp
new file mode 100755
index 0000000..23f4fd3
--- /dev/null
+++ b/contests/Round933/A/main.cpp
@@ -0,0 +1,74 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void solve() {
+  int n, m, k;
+  cin >> n >> m >> k;
+  int cnt = 0;
+  vi b(n);
+  vi c(m);
+  for (auto &x : b) {
+    cin >> x;
+  }
+  for (auto &x : c) {
+    cin >> x;
+  }
+  for (int i = 0; i < n; i++) {
+    for (int j = 0; j < m; j++) {
+      if (b[i] + c[j] <= k) {
+        cnt++;
+      }
+    }
+  }
+  cout << cnt << '\n';
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}
diff --git a/contests/Round933/A/main_input0.txt b/contests/Round933/A/main_input0.txt
new file mode 100644
index 0000000..3b4a7e5
--- /dev/null
+++ b/contests/Round933/A/main_input0.txt
@@ -0,0 +1,13 @@
+4
+4 4 8
+1 5 10 14
+2 1 8 1
+2 3 4
+4 8
+1 2 3
+4 2 7
+1 1 1 1
+2 7
+3 4 2000
+1 1 1
+1 1 1 1
diff --git a/contests/Round933/A/main_output0.txt b/contests/Round933/A/main_output0.txt
new file mode 100644
index 0000000..a649b49
--- /dev/null
+++ b/contests/Round933/A/main_output0.txt
@@ -0,0 +1,4 @@
+6
+0
+4
+12
diff --git a/contests/Round933/B/main.cpp b/contests/Round933/B/main.cpp
new file mode 100755
index 0000000..eae9018
--- /dev/null
+++ b/contests/Round933/B/main.cpp
@@ -0,0 +1,80 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+using ll = long long;
+using pii = pair<int, int>;
+using vpii = vector<pii>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+#define make_unique(x)                                                         \
+  sort(all((x)));                                                              \
+  (x).resize(unique(all((x))) - (x).begin())
+#define ceil(a, b) ((a) + (b)-1) / (b)
+
+const int mod = (int)1e9 + 7;
+const db pi = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+#ifdef LOCAL
+#include "debug.h"
+#else
+#define dbg(...) 42
+#endif
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+void apply(vi &v, int idx, int times) {
+  v[idx] -= 2 * times;
+  v[idx - 1] -= times;
+  v[idx + 1] -= times;
+}
+
+void solve() {
+  int n;
+  cin >> n;
+  vi v(n);
+  for (auto &x : v) {
+    cin >> x;
+  }</