Longest increasing subsecuence

longest-increasing-subsecuence.js

let highest = [];

longest = (sequence) => {
    var ordered = sequence.map(n => n);
    ordered.sort((a, b) => a - b);

    var matrix = {};
    const length = ordered.length;
    for (let i = 0; i < length; i++) {
        for(let j = 0; j < length; j++) {
            if(ordered[i] == sequence[j]) {
                matrix[i,j] = matrix[i-1, j] + 1;
            } else {
                matrix[i,j] = matrix[i-1, j];
            }
        }
    }
};