refactor 572

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_572.java

@@ -41,38 +41,63 @@
  */
 public class _572 {
 
-    public boolean isSubtree(TreeNode s, TreeNode t) {
-        if (s == null && t == null) {
-            return true;
+    public static class Solution1 {
+        public boolean isSubtree(TreeNode s, TreeNode t) {
+            if (s == null && t == null) {
+                return true;
+            }
+            boolean isSubTree = false;
+            if (s != null && t != null && s.val == t.val) {
+                isSubTree = isSameTree(s, t);
+            }
+            if (isSubTree) {
+                return true;
+            }
+            boolean isSubTreeLeft = false;
+            if (s.left != null) {
+                isSubTreeLeft = isSubtree(s.left, t);
+            }
+            if (isSubTreeLeft) {
+                return true;
+            }
+            boolean isSubTreeRight = false;
+            if (s.right != null) {
+                isSubTreeRight = isSubtree(s.right, t);
+            }
+            if (isSubTreeRight) {
+                return true;
+            }
+            return false;
         }
-        boolean isSubTree = false;
-        if (s != null && t != null && s.val == t.val) {
-            isSubTree = isSameTree(s, t);
-        }
-        if (isSubTree) {
-            return true;
-        }
-        boolean isSubTreeLeft = false;
-        if (s.left != null) {
-            isSubTreeLeft = isSubtree(s.left, t);
-        }
-        if (isSubTreeLeft) {
-            return true;
-        }
-        boolean isSubTreeRight = false;
-        if (s.right != null) {
-            isSubTreeRight = isSubtree(s.right, t);
-        }
-        if (isSubTreeRight) {
-            return true;
+
+        private boolean isSameTree(TreeNode p, TreeNode q) {
+            if (p == null || q == null) {
+                return p == q;
+            }
+            return p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
         }
-        return false;
     }
 
-    private boolean isSameTree(TreeNode p, TreeNode q) {
-        if (p == null || q == null) {
-            return p == q;
+    public static class Solution2 {
+        public boolean isSubtree(TreeNode s, TreeNode t) {
+            if (s == null) {
+                return false;
+            }
+            if (same(s, t)) {
+                return true;
+            }
+            return isSubtree(s.left, t) || isSubtree(s.right, t);
+        }
+
+        private boolean same(TreeNode s, TreeNode t) {
+            if (s == null || t == null) {
+                return s == t;
+            }
+            if (s.val != t.val) {
+                return false;
+            }
+            return same(s.left, t.left) && same(s.right, t.right);
         }
-        return p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
+
     }
 }

src/test/java/com/fishercoder/_572Test.java

@@ -11,13 +11,13 @@
  * Created by fishercoder on 5/6/17.
  */
 public class _572Test {
-    private static _572 test;
+    private static _572.Solution1 solution1;
     private static boolean expected;
     private static boolean actual;
 
     @BeforeClass
     public static void setup() {
-        test = new _572();
+        solution1 = new _572.Solution1();
     }
 
     @Test
@@ -33,7 +33,7 @@ public void test1() {
         t.left = new TreeNode(1);
         t.right = new TreeNode(2);
         expected = false;
-        actual = test.isSubtree(s, t);
+        actual = solution1.isSubtree(s, t);
         assertEquals(expected, actual);
     }
 
@@ -49,7 +49,7 @@ public void test2() {
         t.left = new TreeNode(1);
         t.right = new TreeNode(2);
         expected = true;
-        actual = test.isSubtree(s, t);
+        actual = solution1.isSubtree(s, t);
         assertEquals(expected, actual);
     }
 }