refactor 332

fishercoder1534 · fishercoder1534 · commit a973cb099254 · 2019-01-06T06:41:30.000-08:00
diff --git a/src/main/java/com/fishercoder/solutions/_332.java b/src/main/java/com/fishercoder/solutions/_332.java
@@ -33,75 +33,26 @@ All airports are represented by three capital letters (IATA code).
  */
 public class _332 {
 
-    /**credit: https://discuss.leetcode.com/topic/36383/share-my-solution*/
-    public List<String> findItinerary(String[][] tickets) {
-        Map<String, PriorityQueue<String>> flights = new HashMap<>();
-        LinkedList<String> path = new LinkedList<>();
-        for (String[] ticket : tickets) {
-            flights.putIfAbsent(ticket[0], new PriorityQueue<>());
-            flights.get(ticket[0]).add(ticket[1]);
-        }
-        dfs("JFK", flights, path);
-        return path;
-    }
-
-    public void dfs(String departure, Map<String, PriorityQueue<String>> flights, LinkedList path) {
-        PriorityQueue<String> arrivals = flights.get(departure);
-        while (arrivals != null && !arrivals.isEmpty()) {
-            dfs(arrivals.poll(), flights, path);
-        }
-        path.addFirst(departure);
-    }
-
-
-    public static class MyOwnAttempt {
+    public static class Solution1 {
+        /** credit: https://discuss.leetcode.com/topic/36383/share-my-solution */
         public List<String> findItinerary(String[][] tickets) {
-            List<List<String>> allPossibilities = new ArrayList<>();
-            /**Find all tickets that start from JFK first*/
-            List<String[]> JFKStarts = new ArrayList<>();
-            for (String[] ticket : tickets) {
-                if (ticket[0].equals("JFK")) {
-                    JFKStarts.add(ticket);
-                }
-            }
-
-            for (String[] ticket : JFKStarts) {
-                List<String> thisPossibility = new ArrayList<>();
-                thisPossibility.add(ticket[0]);
-                thisPossibility.add(ticket[1]);
-                dfs(ticket, thisPossibility, tickets, allPossibilities);
-            }
-
-            //sort lexicographically and return the smallest
-            Collections.sort(allPossibilities, new ListComparator<>());
-            return allPossibilities.get(0);
-        }
-
-        private void dfs(String[] thisTicket, List<String> thisPossibility, String[][] tickets, List<List<String>> allPossibilities) {
-            if (thisPossibility.size() == tickets.length + 1) {
-                allPossibilities.add(new ArrayList<>(thisPossibility));
-                return;
-            }
+            Map<String, PriorityQueue<String>> flights = new HashMap<>();
+            LinkedList<String> path = new LinkedList<>();
             for (String[] ticket : tickets) {
-                if (!ticket.equals(thisTicket) && thisPossibility.get(thisPossibility.size() - 1).equals(ticket[0])) {
-                    thisPossibility.add(ticket[1]);
-                    dfs(ticket, thisPossibility, tickets, allPossibilities);
-                    thisPossibility.remove(thisPossibility.size() - 1);
-                }
+                flights.putIfAbsent(ticket[0], new PriorityQueue<>());
+                flights.get(ticket[0]).add(ticket[1]);
             }
+            dfs("JFK", flights, path);
+            return path;
         }
 
-        private class ListComparator<T extends Comparable<T>> implements Comparator<List<T>> {
-            @Override
-            public int compare(List<T> o1, List<T> o2) {
-                for (int i = 0; i < Math.min(o1.size(), o2.size()); i++) {
-                    int c = o1.get(i).compareTo(o2.get(i));
-                    if (c != 0) {
-                        return c;
-                    }
-                }
-                return Integer.compare(o1.size(), o2.size());
+        public void dfs(String departure, Map<String, PriorityQueue<String>> flights,
+            LinkedList path) {
+            PriorityQueue<String> arrivals = flights.get(departure);
+            while (arrivals != null && !arrivals.isEmpty()) {
+                dfs(arrivals.poll(), flights, path);
             }
+            path.addFirst(departure);
         }
     }
 }
diff --git a/src/test/java/com/fishercoder/_332Test.java b/src/test/java/com/fishercoder/_332Test.java
@@ -7,30 +7,28 @@
 
 import java.util.List;
 
-/**
- * Created by stevesun on 6/3/17.
- */
 public class _332Test {
-    private static _332 test;
-    private static String[][] tickets;
-    private static List<String> expected;
+  private static _332.Solution1 solution1;
+  private static String[][] tickets;
+  private static List<String> expected;
 
-    @BeforeClass
-    public static void setup() {
-        test = new _332();
-    }
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _332.Solution1();
+  }
 
-    @Test
-    public void test1() {
-        tickets = new String[][]{{"MUC", "LHR"}, {"JFK", "MUC"}, {"SFO", "SJC"}, {"LHR", "SFO"}};
-        expected = test.findItinerary(tickets);
-        CommonUtils.print(expected);
-    }
+  @Test
+  public void test1() {
+    tickets = new String[][] {{"MUC", "LHR"}, {"JFK", "MUC"}, {"SFO", "SJC"}, {"LHR", "SFO"}};
+    expected = solution1.findItinerary(tickets);
+    CommonUtils.print(expected);
+  }
 
-    @Test
-    public void test2() {
-        tickets = new String[][]{{"JFK", "SFO"}, {"JFK", "ATL"}, {"SFO", "ATL"}, {"ATL", "JFK"}, {"ATL", "SFO"}};
-        expected = test.findItinerary(tickets);
-        CommonUtils.print(expected);
-    }
+  @Test
+  public void test2() {
+    tickets = new String[][] {{"JFK", "SFO"}, {"JFK", "ATL"}, {"SFO", "ATL"}, {"ATL", "JFK"},
+        {"ATL", "SFO"}};
+    expected = solution1.findItinerary(tickets);
+    CommonUtils.print(expected);
+  }
 }
