max connected

max_connected.js

function processData(input) {
    "use strict";
    var data = input.split("\n"),
        n = +data[0],
        m = +data[1],
        line = 2,
        adj = [];
    function connect(a, b) {
        var t = adj[b];
        for (let i = 0; i < adj.length; i++) {
            if (adj[i] === t)
                adj[i] = +adj[a];
        }
    };
    function getMax() {
        var d = {}, max = 0;
        for (let e of adj)
            if (typeof d[e] === "undefined")
                d[e] = 1;
            else
                d[e] += 1;
        for (let k in d)
            if (d[k] > max && k > -1)
                max = d[k];
        return max;
    };
    function ijTo1D(i, j) { 
        return i*n + j; 
    };
    function connectPrev(i, j) {        
        if (j > 0 && adj[ijTo1D(i, j-1)] >= 0)             // left
            connect(ijTo1D(i, j), ijTo1D(i, j-1));
        if (i > 0 && adj[ijTo1D(i-1, j)] >= 0)             // up
            connect(ijTo1D(i, j), ijTo1D(i-1, j));
        if (i > 0 && j > 0 && adj[ijTo1D(i-1, j-1)] >= 0)  // left up
            connect(ijTo1D(i, j), ijTo1D(i-1, j-1));
        if (i > 0 && j+1 < m && adj[ijTo1D(i-1, j+1)] >= 0)// right up
            connect(ijTo1D(i, j), ijTo1D(i-1, j+1));
    };
    function printAdj(delimeter) {
        console.log(delimeter);
        for (let i = 0; i < n; i++) {
            let t = [];
            for (let j = 0; j < n; j++) {
                t.push(adj[ijTo1D(i, j)]);
            }
            console.log(t);
        }
        console.log(delimeter);
    };
    while (line < n+2) {
        let elements = data[line].split(" "),
            i = line-2;
        for (let j = 0; j < elements.length; j++) {
            let idx = ijTo1D(i, j);
            if (elements[j] === "0") {
                adj[idx] = -1;
            } else {
                adj[idx] = idx;
                connectPrev(i, j);
            }
        }
        line++;
    }
    console.log(getMax());
};