Sorting: Understanding Bubble Sort

BubbleSort.swift

func bubbleSort(forInput input: inout [Int]) {
    let uptoEndIndex = input.count - 1

    for rearIndex in 0...uptoEndIndex {
        var isAllSorted = true
        for frontIndex in 0..<uptoEndIndex - rearIndex {
            let currentRunning = frontIndex
            let currentRunningAheadByOne = currentRunning + 1
            if input[currentRunning] > input[currentRunningAheadByOne] {
                input.swapAt(currentRunning, currentRunningAheadByOne)
                isAllSorted = false
            }
        }

        if isAllSorted {
            break
        }
    }
}


var unOrderArray = [5,2,13,7,11,3]
bubbleSort(forInput: &unOrderArray)
print(unOrderArray)


func optimisedBubbleSort(forInput input: inout [Int]) {
    let uptoIndex = input.count - 1

    for rearIndex in 0...uptoIndex {
        // Assuming all elements are sorted
        var isAllSorted = true
        
        for frontIndex in 0..<uptoIndex - rearIndex {
            let currentRunning = frontIndex
            let currentRunningAheadByOne = currentRunning + 1
            if input[currentRunning] > input[currentRunningAheadByOne] {
                isAllSorted = false
                input.swapAt(currentRunning, currentRunningAheadByOne)
                continue
            }
        }
        
        // If our assumptions holds true, Then array is sorted. No need go for next Pass
        if isAllSorted {
            break
        }
    }
}


optimisedBubbleSort(forInput: &unOrderArray)
print(unOrderArray)