var twoSum = function(nums, target) {
    const store = {}
    for(let i = 0; i < nums.length; i++){
      let cur = nums[i]
      let diff = target - cur
      // Return answer if the current number was a diff from a previous number
      if(store[cur]!==undefined) return [store[cur], i]
      // Set diff to current index in store
      else store[diff] = i
    }
};