/*
How to rank elements of an integer array based on their sorted order in Swift
-----------------------------------------------------------------------------
Ranking rules:
- Lowest value gets rank 1
- Equal values share the same rank
- Rank increases only when encountering a new unique value
Steps:
1. Print the original array
2. Create a copy of the array
3. Sort the copy
4. Build a map (value → rank)
5. Apply ranks back to the original order
*/
import Foundation
// ------------------------------------------------------------
// Function 1: Print the array
// ------------------------------------------------------------
func printArray(_ arr: [Int]) {
print("Array: \(arr)")
}
// ------------------------------------------------------------
// Function 2: Create a copy of the array
// ------------------------------------------------------------
func copyArray(_ arr: [Int]) -> [Int] {
return arr.map { $0 } // explicit copy
}
// ------------------------------------------------------------
// Function 3: Sort the array copy
// ------------------------------------------------------------
func sortArray(_ arrCopy: inout [Int]) {
arrCopy.sort()
}
// ------------------------------------------------------------
// Function 4: Build a map of value → rank
// ------------------------------------------------------------
func buildRankMap(_ sortedArr: [Int]) -> [Int: Int] {
var map: [Int: Int] = [:]
guard !sortedArr.isEmpty else { return map }
var rank = 1
var previous = sortedArr[0]
map[previous] = rank
for i in 1..<sortedArr.count {
let current = sortedArr[i]
if current != previous {
rank += 1
}
map[current] = rank
previous = current
}
return map
}
// ------------------------------------------------------------
// Function 5: Apply ranks to original array order
// ------------------------------------------------------------
func applyRanks(_ original: [Int], _ rankMap: [Int: Int]) -> [Int] {
return original.map { rankMap[$0]! }
}
// ------------------------------------------------------------
// Main ranking function
// ------------------------------------------------------------
func rankArray(_ arr: [Int]) {
printArray(arr)
if arr.isEmpty { return }
var arrCopy = copyArray(arr)
sortArray(&arrCopy)
let rankMap = buildRankMap(arrCopy)
let ranked = applyRanks(arr, rankMap)
print("Rank: \(ranked)")
}
// ------------------------------------------------------------
// MAIN PROGRAM
// ------------------------------------------------------------
let arr = [33, 99, 10, 25, 47, 11, 77]
rankArray(arr)
/*
run:
Array: [33, 99, 10, 25, 47, 11, 77]
Rank: [4, 7, 1, 3, 5, 2, 6]
*/
