Question

How to find a number in array that appears once in Swift

Answer 1

func numberExistsFewTimes(_ arr: [Int], _ number: Int, _ index: Int) -> Bool {
    for i in 0..<arr.count {
        if arr[i] == number && i != index {
            return true
        }
    }
    
    return false
}

func getSingleNumber(_ arr: [Int]) -> Int {
    for i in 0..<arr.count {
        if !numberExistsFewTimes(arr, arr[i], i) {
            return arr[i]
        }
    }
    
    return -1
}

let arr = [3, 2, 1, 2, 3, 3, 1, 5, 9, 7, 7, 9, 9]

print(getSingleNumber(arr)) 



       
/*
run:
   
5
  
*/

 

70+ SQL courses for beginners and professionals