Sum From Two Arrays

sumOfTwo.js

/*
* a: [1, 2, 3]
* b: [10, 20, 30, 40]
* v: 42
*/

function sumOfTwo(a, b, v) {
    a = new Set(a);
    return b.map((x) => { if (a.has(v - x)) return true;}).some((isValid) => {return isValid});
}

// Failed on last hidden
function sumOfTwo2(a, b, v) {
    aPointer = 0;
    bPointer = 0;
    
    /*
     * Create a set of one to compare against the other. 
     * Sort both and have one in reverse so the index 
     * 'pointers' will just have to be decremented    
    */ 
    a = [...new Set(a)].sort(function (a, b) { return a - b; });
    b.sort(function (a, b) { return a - b; }).reverse();
   
    //
    while (true) {
        sum = a[aPointer] + b[bPointer];
        if (sum === v) {
            return true;
        } else if (sum < v) {
           aPointer += 1; 
           if (aPointer == a.length) {
               aPointer -= 1;
               bPointer -= 1;
               if (bPointer < 0) return false;
           }
        } else {
            bPointer += 1; 
            if (bPointer == b.length) {
               bPointer -= 1;
               aPointer -= 1;
               if (aPointer < 0) return false;
           }
        }
    }   
}