HackerRank - Matrix Rotation - study code written using JavaScript, by a Stanford university student -

MatrixRotation_Standford1.js

var rows,
    cols,
    array = [];

function processData(input) {
    //Enter your code here
    var input = input.split('\n');
    
    var vars = input.shift().split(' ');
    var m = vars[0], // Rows
        n = vars[1], // Cols
        r = vars[2]; // Rotations
    
    for(var i = 0; i < m; i++) {
        array.push(input.shift().split(' '));
    }
    
    rows = m;
    cols = n;
    
    var minD = Math.min(m,n);
    var depth = minD/2;
    
    
    //process.stdout.write(getRingArray(0));
    //process.stdout.write(getRingArray(0));
    
    for(var i = 0; i < depth; i++) {
        doNRotations(r,i);
    }
    
    for(var i = 0; i < rows; i++) {
        process.stdout.write(array[i].join(' ') + '\n');
    }
    
    
} 

function doNRotations(rotationCount, origin) {
    var ra = getRingArray(origin);
    
    //process.stdout.write('pre: '+ ra);
    var rotations = rotationCount % ra.length;
    for(var i = 0; i < rotations; i++) {
        ra.unshift(ra.pop());
    }
    //process.stdout.write('post: '+ ra);
    
    writeRingArray(origin, ra);
}



function getRingArray(origin) {
    var upDown = rows - (origin*2);
    var leftRight = cols - (origin*2);
    
    var ra = [];
    var y = origin,
        x = origin;
    
    for(y = origin; y < rows - origin; y++) {
        ra.push(array[y][x]);
        //process.stdout.write(ra + '\n');
    }
    y--; 
    x++;
    
    for(x; x < cols - origin; x++) {
        ra.push(array[y][x]);
    }
    x--; 
    y--;
    
    for(y; y >= origin; y--) {
        ra.push(array[y][x]);
    }
    y++; 
    x--;
    
    for(x; x > origin; x--) {
        ra.push(array[y][x]);
    }
    
    return ra;
}

function writeRingArray(origin, ra) {
    var upDown = rows - (origin*2);
    var leftRight = cols - (origin*2);
    
    var y = origin,
        x = origin;
        i = 0;
    
    for(y = origin; y < rows - origin; y++) {
        array[y][x] = ra.shift();
    }
    y--; 
    x++;
    
    for(x; x < cols - origin; x++) {
        array[y][x] = ra.shift();
    }
    x--; 
    y--;
    
    for(y; y >= origin; y--) {
        array[y][x] = ra.shift();
    }
    y++; 
    x--;
    
    for(x; x > origin; x--) {
        array[y][x] = ra.shift();
    }
    
    //process.stdout.write('['+x+','+y+']\n');
    
    
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});