代码随想录二刷day60

提示：文章写完后，目录可以自动生成，如何生成可参考右边的帮助文档

---

前言

---

一、力扣84. 柱状图中最大的矩形

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;
    }
}