a common mistake when using Two Sum Go

Direct Answer

A common mistake with How would you solve Two Sum in Go is using the rule without checking its boundary conditions. Scan the slice once while storing each value's index in a map. That can make a valid-looking result fail for an empty input, a nil value, a duplicate, or a different ordering. I prevent it by naming the assumption, testing the boundary, and checking the result against a small hand-worked example.

Deep Dive & Architecture

Scan the slice once while storing each value's index in a map.

For the current value x, look for target-x before storing x; this gives O(n) time and O(n) space.

Storing the current value before checking, which can reuse the same element.

Code Example

func twoSum(nums []int, target int) []int {
  seen := map[int]int{}
  for i, n := range nums {
    if j, ok := seen[target-n]; ok { return []int{j, i} }
    seen[n] = i
  }
  return nil
}

Common Mistakes & Pitfalls

Giving a slogan about How would you solve Two Sum in Go without checking its scope, boundary cases, or trade-offs.