upload

3/G.cpp

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+#include <iostream>
+
+class BinarySearch {
+ private:
+  int n;
+  int k;
+  int* arr;
+
+  bool IsValid(int target) {
+    int chairs = 1;
+    int last_chair = arr[0];
+    for (int i = 0; i < n; ++i) {
+      if (arr[i] - last_chair >= target) {
+        ++chairs;
+        last_chair = arr[i];
+      }
+    }
+    return chairs >= k;
+  }
+
+ public:
+  BinarySearch(int n, int k, int* arr) : n(n), k(k), arr(arr) { }
+
+  int Search() {
+    int left = 0;
+    int right = arr[n - 1] - arr[0] + 1;
+    while (right - left > 1) {
+      int mid = (left + right) / 2;
+      if (IsValid(mid))
+        left = mid;
+      else
+        right = mid;
+    }
+    return left;
+  }
+
+};
+
+int main() {
+  int n, k;
+  std::cin >> n >> k;
+
+  int* chairs = new int[n];
+
+  for (int i = 0; i < n; ++i) {
+    std::cin >> chairs[i];
+  }
+
+  BinarySearch bs(n, k, chairs);
+
+  std::cout << bs.Search();
+
+  return 0;
+}