Shuffler

shuffle-pairings.js

var names = [
    'Bob',
    'Sarah',
    'Josh',
    'Ben',
    'Natalie',
    'Richard'
];

function fillInCombos (combosSoFar, remainingInput) {
    if (remainingInput.length <= 0) {
        return combosSoFar;
    }
    var inputNumber = remainingInput.pop();
    var newCombos = [];
    combosSoFar.forEach(function (combo) {
        combo.forEach(function (entry, index) {
            if (entry === undefined) {
                var newCombo = combo.slice(0, index).concat([inputNumber]).concat(combo.slice(index + 1));
                newCombos.push(newCombo);
            }
        });
    });
    return fillInCombos(newCombos, remainingInput);
}

function generateAllCombos (input) {
    var undefinedArray = Array.apply(null, Array(input.length));
    return fillInCombos([undefinedArray], input.slice());
}

function zip (input1, input2) {
    if (input1.length !== input2.length) {
        console.error('Cannot zip different lengths');
        return;
    }
    var result = [];
    input1.forEach(function (item1, i) {
        result.push([item1, input2[i]]);
    });
    return result;
}

function generateAllValidPairings (input) {
    var combos = generateAllCombos(input);
    var validPairings = [];
    combos.forEach(function (combo) {
        var pairing = zip(input, combo);
        var isValid = true;
        pairing.forEach(function (pair) {
            if(pair[0] === pair[1]) {
                isValid = false;
            }
        });
        if (isValid) {
            validPairings.push(pairing);
        }
    });
    return validPairings;
}

function displayPairing (pairing) {
    var pairs = [];
    pairing.forEach(function (pair) {
        pairs.push(pair[0] + ' -> ' + pair[1]);
    });
    return pairs.join('; ');
}

function displayAllPairings (pairings) {
    var pairingArray = [];
    pairings.forEach(function (pairing) {
        pairingArray.push(displayPairing(pairing));
    });
    return pairingArray.join('\n');
}

console.log(displayAllPairings(generateAllValidPairings(names)));