LeetCode:Largest Rectangle in Histogram(直方图中最大矩形面积)

84. Largest Rectangle in Histogram

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.

求最大矩形的面积

方法一：暴力来leetcode上也能通过，方法也非常的好理解，就是遍历到每一个高度，向左和向右遍历，找到低于该高度的边界顺便计算矩形的宽度，进而计算面积，最终找到面积的最大值。

class Solution {
public:
    int largestRectangleArea(vector<int>& heights) {
        if(heights.size()==0){
            return 0;