给定 n 个非负整数,用来表示柱状图中各个柱子的高度。每个柱子彼此相邻,且宽度为 1 。
求在该柱状图中,能够勾勒出来的矩形的最大面积。
示例 1:
输入:heights = [2,1,5,6,2,3] 输出:10 解释:最大的矩形为图中红色区域,面积为 10
示例 2:
输入: heights = [2,4] 输出: 4
提示:
1 <= heights.length <=105
0 <= heights[i] <= 104
class Solution { public: void cal(vector<int>& heights, vector<int>& dp) { dp.push_back(-1); for(int i = 1; i < heights.size(); i++) { if(heights[i] > heights[i - 1]) dp.push_back(i - 1); else { int k = dp[i - 1]; while(k != -1 && heights[i] <= heights[k]) { k = dp[k]; } dp.push_back(k); } } } int largestRectangleArea(vector<int>& heights) { vector<int> heightscopy; for(int i = heights.size() - 1; i >= 0; i--) { heightscopy.push_back(heights[i]); } vector<int> dp1, dp2; cal(heights, dp1); cal(heightscopy, dp2); int ret = 0, n = heights.size(); for(int i = 0; i < n; i++) { ret = max(ret, heights[i] * (i - dp1[i] + n - i - 1 - dp2[n - i - 1] - 1)); } return ret; } };