s6-ex4.js

function areThereDuplicates() {
    // Time complexity : O(n)
    // Space complexity : O(n) 
    if (arguments.length < 2) return true;

    let dups = {};

    for (let a in arguments)
    {
        if (dups[arguments[a]]) return true;
        else dups[arguments[a]] = 1;
    }

    return false;
}

function areThereDuplicatesBonus(...args) {
    // Time complexity : O(n log(n))
    // Space complexity : O(1) 
    if (arguments.length < 2) return true;

    args.sort( (a,b) => a > b);

    let start = 0;
    let next = 1;

    while (next < args.length)
    {
        if(args[start] === args[next]) return true;

        start++;
        next++;
    }

    return false;
}


// console.log(areThereDuplicates(1, 2, 3)); // False
// console.log(areThereDuplicates(1, 2, 2)); // True
// console.log(areThereDuplicates("a", "b", "c", "a")); // True

console.log(areThereDuplicatesBonus(1, 2, 3)); // False
console.log(areThereDuplicatesBonus(1, 2, 2)); // True
console.log(areThereDuplicatesBonus("a", "b", "c", "a")); // True