二分查找：在有序数组中寻找小于k的最大元素的C++实现

```cpp #include <iostream> #include <vector> // 二分查找小于k的最大元素 int binarySearch(const std::vector<int>& arr, int k) { int left = 0, right = arr.size() - 1; int result = -1; while (left <= right) { int mid = left + (right - left) / 2; if (arr[mid] < k) { result = arr[mid]; left = mid + 1; } else { right = mid - 1; } } return result; } int main() { int n; std::cin >> n; std::vector<int> arr(n); for (int i = 0; i < n; ++i) { std::cin >> arr[i]; } int k; std::cin >> k; int ans = binarySearch(arr, k); std::cout << ans << std::endl; return 0; } ``` ######[AI问答 | 272点数解答 | 2026-04-11 20:16:33]