In other words, understand that if arr[pointer_one] < target-arr[pointer_two], it means we should move forward on pointer_one to get closer to where we want to be in magnitude.
This is what it looks like all put together:
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var twoSum = function (arr, target) { for (let i = 0, j = arr.length - 1; i < j; ) { let sum = arr[i] + arr[j]; if (sum === target) { return [i + 1, j + 1]; } else if (sum < target) { i++; } else { j--; } }};​console.log(twoSum([1, 3, 4, 8, 9], 11));OUTPUT
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