原题链接在这里：

题目：

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 01 0 1 1 11 1 1 1 11 0 0 1 0

Return 6.

题解：

用数组heights存储一行中值为1的点的最大高度，然后像算这一行能产生的最大面积maxRec.

Time Complexity: O(m*n). m = matrix.length. n = matrix[0].length.

Space: O(n).

AC Java:

1 class Solution { 2     public int maximalRectangle(char[][] matrix) { 3         if(matrix == null || matrix.length == 0 || matrix[0].length == 0){ 4             return 0; 5         } 6          7         int res = 0; 8         int m = matrix.length; 9         int n = matrix[0].length;10         int [] heights = new int[n];11         for(int i = 0; i
     
       stk = new Stack
      
       ();30         stk.push(-1);31         for(int i = 0; i
       
        =heights[i]){33                 int h = heights[stk.pop()];34                 res = Math.max(res, h*(i-stk.peek()-1));35             }36             37             stk.push(i);38         }39         40         while(stk.peek() != -1){41             res = Math.max(res, heights[stk.pop()]*(heights.length-stk.peek()-1));42         }43         44         return res;45     }46 }
       
      
     

类似.