Write a function called sumZero which accepts a sorted array of integers. The function should find the first pair where the sum is 0. Return an array that includes both values that sum to zero or undefined if a pair doesn’t exist.

multi pointer pattern

Following is sample javascript code.

function sumZero(arr) {
    let left = 0;
    let right = arr.length - 1;
    while(left < right){
        let sum = arr[left] + arr[right];

        if(sum === 0) {
            return [arr[left], arr[right]];
        } else if(sum>0) {
            right --;
        } else if(sum === 0){
          console.log("hey this is false positive because 0 - 0 = 0");
          return "+/-0"
        }else {
            left ++;
        }
        
    }
    
};

input:
console.log(sumZero([-4,-3,-2,-1,0,1,2,3,10]));

Output:

[ -3, 3 ]