Leetcode 84. Largest Rectangle in Histogram (Hard) (cpp)

Leetcode 84. Largest Rectangle in Histogram (Hard) (cpp)

Tag: Array, Stack

Difficulty: Hard

/*84. Largest Rectangle in Histogram (Hard)Given n non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.Above is a histogram where width of each bar is 1, given height = [2,1,5,6,2,3].The largest rectangle is shown in the shaded area, which has area = 10 unit.For example,Given heights = [2,1,5,6,2,3],return 10.*/class Solution {public:int largestRectangleArea(vector<int>& heights) {stack<int> s;int res = 0;for (int i = 0; i <= heights.size(); i++) {int cur = i == heights.size() ? 0 : heights[i];while (!s.empty() && cur <= heights[s.top()]) {int height = heights[s.top()];s.pop();int left = s.empty() ? 0 : s.top() + 1;res = max(res, height * (i - left));}s.push(i);}return res;}};