LeetCode[85]::Maximal Rectangle C++

Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.

class Solution {
public:
    int maximalRectangle(vector>& matrix) {
        int m = matrix.size();
        if(m == 0){
            return 0;
        }
        
        int n = matrix[0].size();
        if(n == 0){
            return 0;
        }
        
        vector count(n, 0);
        vector isProcessed(n, false);
        
        int area = 0;
        
        for(size_t i = 0; i < m; ++i){
            for(size_t j = 0; j < n; ++j){
                if(matrix[i][j] == '0'){
                    count[j] = 0;
                    isProcessed[j] = true;
                }else{
                    count[j]++;
                    isProcessed[j] = false;
                }
            }
            
            for(size_t j = 0; j < n; ++j){
                if(isProcessed[j]){
                    continue;
                }
                int biasLeft = 1;
                int biasRight = 1;
                while( (j-biasLeft >= 0) && (count[j-biasLeft] >= count[j]) ){
                    if(count[j-biasLeft] == count[j]){
                        isProcessed[j-biasLeft] = true;
                    }
                    biasLeft++;
                }
                while( (j+biasRight < n) && (count[j+biasRight] >= count[j]) ){

                    biasRight++;
                }
                
                area = max(area, (biasRight + biasLeft - 1)*count[j]);
            }
        }
        return area;
    }
};