一句话总结：完结撒花！

原题链接：84 柱状图中最大的矩形

与接雨水的单调栈做法类似。代码如下：

class Solution {public int largestRectangleArea(int[] heights) {int[] newHeight = new int[heights.length + 2];System.arraycopy(heights, 0, newHeight, 1, heights.length);newHeight[heights.length+1] = 0;newHeight[0] = 0;Stack<Integer> stack = new Stack<>();stack.push(0);int res = 0;for (int i = 1; i < newHeight.length; i++) {while (newHeight[i] < newHeight[stack.peek()]) {int mid = stack.pop();int w = i - stack.peek() - 1;int h = newHeight[mid];res = Math.max(res, w * h);}stack.push(i);}return res;}
}