gistfile1.txt

import UIKit
import XCTest

// experimenting with strings
// remove string at given indexes

extension String {

    // just a convenience method to visualize indexes
    func printIndexes() {
        for (i, char) in enumerated() {
            print("\(i): \(char)")
        }
    }
    
    
    // easy String subscript
    func subString(from: Int, to: Int) -> String {
        let startIndex = self.index(self.startIndex, offsetBy: from)
        let endIndex = self.index(self.startIndex, offsetBy: to)
        return String(self[startIndex..<endIndex])
    }
    
    
    func remove2(at indexes: [Int]) -> String {
        
        var result = ""
        var currentOffset = 0
        for i in indexes {
            result.append(subString(from: currentOffset, to: i))
            currentOffset = i + 1
        }
        result.append(subString(from: currentOffset, to: self.count))
        
        return result
    }
    
    func remove(at indices: [Int]) -> String {

        var output = ""
        for (i, char) in Array(str).enumerated() {
            if !indices.contains(i) {
                output.append(contentsOf: "\(char)")
            }
        }
        return output
    }
    
}

var str = "Pomerode"

class Performancer: XCTestCase {

    func testOne() {
        measure {
            str.remove(at: [1,4,7])
        }
    }
    
    func testTwo() {
        measure {
            str.remove2(at: [1,4,7])
        }
    }
}

Performancer.defaultTestSuite.run()