How to solve this Swift problem (AP CP Principles - Structures) - swift

Question

I am currently going through Apple Curriculum books and stumbled across a problem I can't figure out.
There is a structure:
struct Song {
let title: String
let artist: String
let duration: Int
var longestSong = false
}
and an array with 4 songs that have different duration: 90, 200, 150, 440.
The book asks to add a method that checks whether one song is longer than the other.
So, based on previous material I added the following method to my struct:
func isLongerThan(_ song: Song) -> Bool {
return duration > song.duration
}
}
Then the book asks to use a loop in order to find the longest song in the array and print it to the console
(Hint: use a variable to keep track of the longest song and initialize
it to the first one in the array.)
So, I came up with this loop:
for (index, _) in songs.enumerated() {
if index < songs.count-1{
if songs[index].isLongerThan(songs[index + 1]){
songs[index].longestSong = true
print("\(songs[index].title) is longer than \(songs[index+1].title)")
}
} else {
if songs[songs.count-1].isLongerThan(songs[0]){
songs[songs.count-1].longestSong = true
print("\(songs[songs.count-1].title) is longer than \(songs[0].title)")
}
}
}
The next step is to compare those songs with longestSong = true variable until only one song remains. But this isn't a good solution in my opinion.
Is there a better and more elegant way to solve this problem?
UPD
It seems that I have misread the instructions and have gone the wrong way.
With some help I managed to find this solution:
func searchForLongestSong(songs: [Song]) {
var lngstSongIndex = 0
for song in 0..<songs.count {
if songs[song].duration > songs[lngstSongIndex].duration {
lngstSongIndex = song
}
}
print("The longst song is \"\(songs[lngstSongIndex].title)\"")
}
searchForLongestSong(songs: songs)

Answer 1

Since it is an Array you can keep track of the "longest song" by saving the index of the longest song.
Create an Int var to save the index.
Loop through the indices for n in 0..<songs.count
if the duration of songs[n] is greater than songs[largestSongIdx]
Then update the longestSong variables for both accordingly