add 937

fishercoder1534 · fishercoder1534 · commit b7da55ce14bb · 2019-01-22T18:35:35.000-08:00
diff --git a/README.md b/README.md
@@ -41,6 +41,7 @@ Your ideas/fixes/algorithms are more than welcome!
 |944|[Delete Columns to Make Sorted](https://leetcode.com/problems/delete-columns-to-make-sorted/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_944.java) | O(n) | O(1) | |Easy|
 |941|[Valid Mountain Array](https://leetcode.com/problems/valid-mountain-array/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_941.java) | O(n) | O(1) | |Easy|
 |938|[Range Sum of BST](https://leetcode.com/problems/range-sum-of-bst/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_938.java) | O(n) | O(n) | |Medium| BST, recursion, DFS
+|937|[Reorder Log Files](https://leetcode.com/problems/reorder-log-files/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_937.java) | O(n) | O(n) | |Easy|
 |933|[Number of Recent Calls](https://leetcode.com/problems/number-of-recent-calls/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_933.java) | O(n) | O(n) | |Easy|
 |929|[Unique Email Addresses](https://leetcode.com/problems/unique-email-addresses/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_929.java) | O(n) | O(n) | |Easy|
 |925|[Long Pressed Name](https://leetcode.com/problems/long-pressed-name/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_925.java) | O(n) | O(1) | |Easy|
diff --git a/src/main/java/com/fishercoder/solutions/_937.java b/src/main/java/com/fishercoder/solutions/_937.java
@@ -0,0 +1,60 @@
+package com.fishercoder.solutions;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.TreeMap;
+
+/**
+ * 937. Reorder Log Files
+ *
+ * You have an array of logs.  Each log is a space delimited string of words.
+ *
+ * For each log, the first word in each log is an alphanumeric identifier.  Then, either:
+ *
+ * Each word after the identifier will consist only of lowercase letters, or;
+ * Each word after the identifier will consist only of digits.
+ * We will call these two varieties of logs letter-logs and digit-logs.  It is guaranteed that each log has at least one word after its identifier.
+ *
+ * Reorder the logs so that all of the letter-logs come before any digit-log.
+ * The letter-logs are ordered lexicographically ignoring identifier, with the identifier used in case of ties.
+ * The digit-logs should be put in their original order.
+ *
+ * Return the final order of the logs.
+ *
+ * Example 1:
+ *
+ * Input: ["a1 9 2 3 1","g1 act car","zo4 4 7","ab1 off key dog","a8 act zoo"]
+ * Output: ["g1 act car","a8 act zoo","ab1 off key dog","a1 9 2 3 1","zo4 4 7"]
+ *
+ * Note:
+ * 0 <= logs.length <= 100
+ * 3 <= logs[i].length <= 100
+ * logs[i] is guaranteed to have an identifier, and a word after the identifier.
+ */
+public class _937 {
+  public static class Solution1 {
+    public String[] reorderLogFiles(String[] logs) {
+      TreeMap<String, String> letterLogMap = new TreeMap<>();
+      List<String> digitLogList = new ArrayList<>();
+      for (String log : logs) {
+        int firstSpaceIndex = log.indexOf(' ');
+        String id = log.substring(0, firstSpaceIndex);
+        if (Character.isAlphabetic(log.charAt(firstSpaceIndex + 1))) {
+          String key = log.substring(firstSpaceIndex + 1) + id;
+          letterLogMap.put(key, log);
+        } else {
+          digitLogList.add(log);
+        }
+      }
+      String[] reorderedLogs = new String[logs.length];
+      int i = 0;
+      for (String key : letterLogMap.keySet()) {
+        reorderedLogs[i++] = letterLogMap.get(key);
+      }
+      for (String log : digitLogList) {
+        reorderedLogs[i++] = log;
+      }
+      return reorderedLogs;
+    }
+  }
+}
diff --git a/src/test/java/com/fishercoder/_937Test.java b/src/test/java/com/fishercoder/_937Test.java
@@ -0,0 +1,33 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._937;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class _937Test {
+  private static _937.Solution1 solution1;
+  private static String[] logs;
+  private static String[] expected;
+
+  @BeforeClass
+  public static void setup() {
+    solution1 = new _937.Solution1();
+  }
+
+  @Test
+  public void test1() {
+    logs = new String[] {"a1 9 2 3 1", "g1 act car", "zo4 4 7", "ab1 off key dog", "a8 act zoo"};
+    expected =
+        new String[] {"g1 act car", "a8 act zoo", "ab1 off key dog", "a1 9 2 3 1", "zo4 4 7"};
+    assertArrayEquals(expected, solution1.reorderLogFiles(logs));
+  }
+
+  @Test
+  public void test2() {
+    logs = new String[] {"t kvr", "r 3 1", "i 403", "7 so", "t 54"};
+    expected = new String[] {"t kvr", "7 so", "r 3 1", "i 403", "t 54"};
+    assertArrayEquals(expected, solution1.reorderLogFiles(logs));
+  }
+}
