Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area. 思路: 例如 01101 11010 01110 11110 11111 00000 按列从上到下计算maximal rectangle: 01101 12010 03110 14210 25321 00000 然后对每一行求直方图的最大面积,于是这个问题可以转化…

一.题目说明 题目,85. Maximal Rectangle,计算只包含1的最大矩阵的面积.难度是Hard! 二.我的解答 看到这个题目,我首先想到的是dp,用dp[i][j]表示第i行第j列元素向右下角计算的最大面积.后来发现从dp[i+1][j].dp[i][j+1]和dp[i+1][j+1]计算dp[i][j]几乎没有任何规律可循. 然后,我就想用down_dp[i][j]和right_dp[i][j]两个dp,但遗憾的是还是没成功. 后面看了大神的写法,其实down_dp[i][j]然…

85. Maximal Rectangle Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing only 1's and return its area. For example, given the following matrix: 1 0 1 0 0 1 0 1 1 1 0 0 1 0 Return 6.…

Maximal Rectangle Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area. 如果用DP来做,判断(begin1,end1)~(begin2,end2)范围是否全1,会超时. 对于矩阵matrix,逐行构建height数组,调用Largest Rectangle in Histogram即可. 对matr…

Given a rows x cols binary matrix filled with 0's and 1's, find the largest rectangle containing only 1's and return its area. Example 1: Input: matrix = [["1","0","1","0","0"],["1","0"…

之前切了道求解最大正方形的题,题解猛戳 这里.这道题 Maximal Rectangle 题意与之类似,但是解法完全不一样. 先来看这道题 Largest Rectangle in Histogram,如果暴力求解,可以枚举每个点为最小值,向两边扩展,复杂度 O(n^2).我们可以维护一个栈,从而将复杂度降低到 O(n),这个栈的思维非常巧妙,参考了 discuss,我是完全想不出来(或者说忘记了).具体代码可以猛戳 这里. 2016-08-07 补:stack 数组维护的是一个单调递增的数组,…

链接: https://leetcode.com/problems/maximal-rectangle/ [描述] Given a 2D binary matrix filled with '0's and '1's, find the largest rectangle containing all ones and return its area. [中文描述] 给一个二维数组, 算出里面最大的全1矩形面积,比如: [ ['1','1','1','0'], ['1','1','1','1']…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址: https://leetcode.com/problems/maximal-rectangle/description/ 题目描述: Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing only 1's and return its area. Exa…

给定一个只含0和1的数组,求含1的最大矩形面积. Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area. 这样的题一般看来都是有O(n*m)的解法的. 借助上一题Largest Rectangle in Histogram 的解法. 我们现在把矩阵的每一行当做是上一题的问题,然后遍历所有的行数,取最大数就是解. 这里的…

1. 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 large…