For Swift

let longRoutes = [["San Policarpo", "Oras"], ["Balangiga", "Lawaan"], ["Borongan", "Maydolong"], ["Jipapad", "Maslog"], ["Balangkayan", "Llorente"], ["Mercedes", "Guiuan"], ["Taft", "Sulat"], ["Sulat", "San Julian"], ["Arteche", "San Policarpo"], ["Oras", "Dolores"], ["Dolores", "Can-avid"], ["Can-avid", "Taft"], ["San Julian", "Borongan"], ["Maydolong", "Balangkayan"], ["Llorente", "Hernani"], ["Hernani", "General MacArthur"], ["General MacArthur", "Giporlos"], ["Giporlos", "Balangiga"], ["Lawaan", "Salcedo"], ["Salcedo", "Mercedes"], ["Maslog", "Arteche"]]

XCTAssertEqual(findRoutes(routes: longRoutes), "Jipapad, Maslog, Arteche, San Policarpo, Oras, Dolores, Can-avid, Taft, Sulat, San Julian, Borongan, Maydolong, Balangkayan, Llorente, Hernani, General MacArthur, Giporlos, Balangiga, Lawaan, Salcedo, Mercedes, Guiuan")