Largest Submatrix With Rearrangements.js

var largestSubmatrix = function(matrix) {
    let n = matrix.length;
    let m = matrix[0].length;
    let col = new Array(m).fill(0);
    let res = 0;
    for(let i = 0; i < n; i++){
        for(let j = 0; j < m; j++){
            if(matrix[i][j]) col[j]++;
            else col[j] = 0;
        }
        res = counting(col, res);
    }
    return res;
};


//if you did 84. Largest Rectangle in Histogram, you can replace the following part with your 84 answer and don't forget to sort.
let counting = function(column, max) {
     let sorted = [...column].sort((a,b)=>b-a);
     let k, j;
    for (let i=0; i < sorted.length ;i++){
        if(sorted[i]===sorted[i-1]) continue;  
        k = j = i;
        while(sorted[j]&&sorted[j]>=sorted[i]) j++;
        while(sorted[k]&&sorted[k]>=sorted[i]) k--;
        max = Math.max(sorted[i]*Math.abs(k-j+1), max);
    }
    return max;
};