add: 220129

2201/220129.cpp

@@ -0,0 +1,52 @@
+#include <vector>
+#include <iostream>
+#include <random>
+#include <queue>
+#include <ctime>
+#include <chrono>
+
+class Solution {
+private:
+	// Interval [L, R)
+	static int dAC(const std::vector<int>& heights, int L, int R) {
+		if (R - L <= 1)
+			return heights[L];
+		const auto minPos = std::distance(heights.begin(), std::min_element(heights.begin() + L, heights.begin() + R));
+		const auto minVal = heights[minPos];
+		int ans = (R - L) * minVal;
+		if (minPos - L >= 1) {
+			int nextR = minPos;
+			while (nextR - L > 1 && heights[nextR - 1] <= minVal)
+				--nextR;
+			ans = std::max(ans, dAC(heights, L, nextR));
+		}
+		if (R - minPos > 1) {
+			int nextL = minPos + 1;
+			while (R - nextL > 1 && heights[nextL] <= minVal)
+				++nextL;
+			ans = std::max(ans, dAC(heights, nextL, R));
+		}
+		return ans;
+	}
+public:
+	static int largestRectangleArea(const std::vector<int>& heights) {
+		return dAC(heights, 0, heights.size());
+	}
+};
+
+int main() {
+	std::vector<int> sample{3, 6, 5, 7, 4, 8, 1, 0};
+	std::cout << Solution::largestRectangleArea(sample) << std::endl;
+	const int LIM = 100000;
+	std::mt19937 r(time(nullptr));
+	std::vector<int> arg;
+	arg.reserve(LIM);
+	for (int i = 0; i < LIM; ++i) {
+		arg.push_back(r() % 10000);
+	}
+	const auto start = std::chrono::high_resolution_clock::now();
+	std::cout << Solution::largestRectangleArea(arg) << std::endl;
+	const auto end = std::chrono::high_resolution_clock::now();
+	std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count() << " ms.\n";
+	return 0;
+}