Find the second largest number and its Index

Code

func findSecondLargest(arr: [Int]) -> (number: Int, index: Int)? {
    var largest = Int.min
    var secondLargest = Int.min
    var largestIndex = -1
    var secondLargestIndex = -1

    for (index, num) in arr.enumerated() {
        if num > largest {
            secondLargest = largest
            secondLargestIndex = largestIndex
            largest = num
            largestIndex = index
        } else if num > secondLargest && num != largest {
            secondLargest = num
            secondLargestIndex = index
        }
    }

    // If a second largest number was found, return it along with its index
    if secondLargestIndex != -1 {
        return (number: secondLargest, index: secondLargestIndex)
    } else {
        return nil // No second largest number found
    }
}

Example

// Example usage
let array = [5, 2, 18, 3, 4, 7, 1, 6, 3]
if let result = findSecondLargest(arr: array) {
    print("Second largest number: \(result.number)")
    print("Index: \(result.index)")
} else {
    print("No second largest number found.")
}

Output

Second largest number: 7
Index: 5