Daily Coder Problem March 13, 2020

daily_coder_march_13_2020.swift

/*
Given a list of numbers and a number k, return whether any two numbers from the list add up to k.

For example, given [10, 15, 3, 7] and k of 17, return true since 10 + 7 is 17.

Bonus: Can you do this in one pass?
*/

let testArray = [10, 15, 3, 7]
let testTarget = 17

enum TargetResult {
  case notFound
  case found(index1: Int, index2: Int)
}

func doesTarget(_ target: Int, existIn array: [Int]) -> TargetResult {
  var complementMap: [Int: Int] = [:]
  for (index, i) in array.enumerated() {
    let complement = target - i
    if let complementIndex = complementMap[complement] {
      return .found(index1: index, index2: complementIndex)
    }
    complementMap[i] = index
  }
  return .notFound
}

print(doesTarget(testTarget, existIn: testArray))