import Foundation
func removeNewlines(_ s: String) -> String {
let collapsed = s.replacingOccurrences(of: "\\s+", with: " ", options: .regularExpression)
return collapsed.trimmingCharacters(in: .whitespacesAndNewlines)
}
let s = "c# \n c c++ \n java python\ngo\n";
let result = removeNewlines(s)
print(result)
/*
run:
c# c c++ java python go
*/