DSA using JavaScript

Two Pointers

function findPairBruteForce(arr, target) {
    for (let i = 0; i < arr.length; i++) {
        for (let j = i + 1; j < arr.length; j++) {
            if (arr[i] + arr[j] === target) {
                return [arr[i], arr[j]];
            }
        }
    }
    return null;
}

const arr = [1, 2, 4, 7, 11, 15];
const target = 9;
console.log(findPairBruteForce(arr, target));

function findPairTwoPointer(arr, target) {
    let low = 0;
    let high = arr.length - 1;

    while (low < high) {
        const sum = arr[low] + arr[high];
        if (sum === target) {
            return [arr[low], arr[high]];
        } else if (sum < target) {
            low++;
        } else {
            high--;
        }
    }
    return null;
}

const arr = [1, 2, 4, 7, 11, 15];
const target = 9;
console.log(findPairTwoPointer(arr, target));