Design a function that takes two string parameters. The function should return the longest substring that fully matches the provided pattern. Assume that the input and pattern characters are alphabetic.

find_match.swift

import UIKit
import Foundation

/** Design a function that takes two string parameters:
 input
 pattern

The function should return the longest substring that fully matches
the provided pattern. Assume that the input and pattern characters are
alphabetic.

 find_match("abcdcef", "cd") -> "cd"

Function prototype:
 string find_match(string input, string pattern);

**/

func find_match(input:String, pattern:String) -> String {
    var endOffset = pattern.count
    var result = ""
    while(endOffset >= 1) {
        var match = String(pattern.prefix(upTo: pattern.index(pattern.startIndex, offsetBy:endOffset)))
        if(input.contains(match)) {
            result = match
            break
        } else {
            match = String(pattern.suffix(pattern.count - endOffset + 1))
            if(input.contains(match)){
                result = match
                break
            }
        }
        endOffset-=1
    }
    return result
}

let resultOne = find_match(input: "catwithacap", pattern: "cat")
let resultTwo = find_match(input: "abcdefg", pattern: "cd")
let resultThree = find_match(input: "doginthedogecoin", pattern: "dog")
let resultFour = find_match(input: "CodingAndInterviews", pattern: "CodingQuiz")
print(resultOne, resultTwo, resultThree, resultFour) // cat cd dog Coding