Discussion on: Daily Coding Problem #1

[Tiago Romero Garcia]

Here is my O(N) solution using Set:

function doTwoNumbersSumUpToK(list, k) {
    const visitedNumbers = new Set();
    for (let number of list) {
        visitedNumbers.add(number);
        if (visitedNumbers.has(k-number)) {
            return true;
        }
    }
    return false;
}

[Adi biton]

You should move line:
visitedNumbers.add(number);

after the if clause (otherwise the sums like 4+4=8 will be counted)

A compare i made for the Set vs HashTable
jsperf.com/add-to-k