Swift Language Algorithms with Swift Insertion Sort
Example
Insertion sort is one of the more basic algorithms in computer science. The insertion sort ranks elements by iterating through a collection and positions elements based on their value. The set is divided into sorted and unsorted halves and repeats until all elements are sorted. Insertion sort has complexity of O(n2). You can put it in an extension, like in an example below, or you can create a method for it.
extension Array where Element: Comparable {
func insertionSort() -> Array<Element> {
//check for trivial case
guard self.count > 1 else {
return self
}
//mutated copy
var output: Array<Element> = self
for primaryindex in 0..<output.count {
let key = output[primaryindex]
var secondaryindex = primaryindex
while secondaryindex > -1 {
if key < output[secondaryindex] {
//move to correct position
output.remove(at: secondaryindex + 1)
output.insert(key, at: secondaryindex)
}
secondaryindex -= 1
}
}
return output
}
}
