[Leetcode] 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.

Solution:

public class Solution {
    public int maximalRectangle(char[][] matrix) {
        if (matrix.length == 0||matrix[0].length==0)
            return 0;
        int row = matrix.length;
        int col = matrix[0].length;
        int[][] temp = new int[row][col];
        for(int i=0;i<col;++i){
            temp[0][i]=(matrix[0][i]=='1')?1:0;
        }
        for(int i=1;i<row;++i){
            for(int j=0;j<col;++j){
                temp[i][j]=(matrix[i][j]=='1')?(temp[i-1][j]+1):0;
            }
        }
        int maxArea=0;
        for(int i=row-1;i>=0;--i){
            int tempArea=getArea(temp[i]);
            maxArea=Math.max(maxArea, tempArea);
        }
        return maxArea;
    }

    private int getArea(int[] temp) {
        // TODO Auto-generated method stub
        int max=0;
        for(int position=0;position<temp.length;++position){
            int tempMax=0;
            int currentVal=temp[position];
            tempMax+=currentVal;
            int left=position-1;
            int right=position+1;
            while(left>=0&&temp[left]>=currentVal){
                tempMax+=currentVal;
                left--;
            }
            while(right<temp.length&&temp[right]>=currentVal){
                tempMax+=currentVal;
                right++;
            }
            max=Math.max(max, tempMax);
        }
        return max;
    }
}