add a solution for 617

fishercoder1534 · fishercoder1534 · commit e787afd8071e · 2021-09-20T07:20:46.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_617.java b/src/main/java/com/fishercoder/solutions/_617.java
@@ -5,18 +5,35 @@
 public class _617 {
 
     public static class Solution1 {
-        public TreeNode mergeTrees(TreeNode t1, TreeNode t2) {
-            if (t1 == null) {
-                return t2;
+        public TreeNode mergeTrees(TreeNode root1, TreeNode root2) {
+            if (root1 == null) {
+                return root2;
             }
-            if (t2 == null) {
-                return t1;
+            if (root2 == null) {
+                return root1;
             }
-            TreeNode mergedNode = new TreeNode(t1.val + t2.val);
-            mergedNode.left = mergeTrees(t1.left, t2.left);
-            mergedNode.right = mergeTrees(t1.right, t2.right);
+            TreeNode mergedNode = new TreeNode(root1.val + root2.val);
+            mergedNode.left = mergeTrees(root1.left, root2.left);
+            mergedNode.right = mergeTrees(root1.right, root2.right);
             return mergedNode;
         }
     }
 
+    public static class Solution2 {
+        /**
+         * My completely original solution on 9/20/2021, no new extra nodes created.
+         */
+        public TreeNode mergeTrees(TreeNode root1, TreeNode root2) {
+            if (root1 == null) {
+                return root2;
+            } else if (root2 == null) {
+                return root1;
+            }
+            root1.val += root2.val;
+            root1.left = mergeTrees(root1.left, root2.left);
+            root1.right = mergeTrees(root1.right, root2.right);
+            return root1;
+        }
+    }
+
 }
diff --git a/src/test/java/com/fishercoder/_617Test.java b/src/test/java/com/fishercoder/_617Test.java
@@ -11,15 +11,22 @@
 
 public class _617Test {
     private static _617.Solution1 solution1;
+    private static _617.Solution2 solution2;
 
     @BeforeClass
     public static void setup() {
         solution1 = new _617.Solution1();
+        solution2 = new _617.Solution2();
     }
 
     @Test
     public void test1() {
         assertEquals(TreeUtils.constructBinaryTree(Arrays.asList(3, 4, 5, 5, 4, null, 7)), solution1.mergeTrees(TreeUtils.constructBinaryTree(Arrays.asList(1, 3, 2, 5)), TreeUtils.constructBinaryTree(Arrays.asList(2, 1, 3, null, 4, null, 7))));
     }
 
+    @Test
+    public void test2() {
+        assertEquals(TreeUtils.constructBinaryTree(Arrays.asList(3, 4, 5, 5, 4, null, 7)), solution2.mergeTrees(TreeUtils.constructBinaryTree(Arrays.asList(1, 3, 2, 5)), TreeUtils.constructBinaryTree(Arrays.asList(2, 1, 3, null, 4, null, 7))));
+    }
+
 }

Original file line number	Diff line number	Diff line change
`@@ -11,15 +11,22 @@`
`11`	`11`
`12`	`12`	`public class _617Test {`
`13`	`13`	`private static _617.Solution1 solution1;`
	`14`	`+ private static _617.Solution2 solution2;`
`14`	`15`
`15`	`16`	`@BeforeClass`
`16`	`17`	`public static void setup() {`
`17`	`18`	`solution1 = new _617.Solution1();`
	`19`	`+ solution2 = new _617.Solution2();`
`18`	`20`	`}`
`19`	`21`
`20`	`22`	`@Test`
`21`	`23`	`public void test1() {`
`22`	`24`	`assertEquals(TreeUtils.constructBinaryTree(Arrays.asList(3, 4, 5, 5, 4, null, 7)), solution1.mergeTrees(TreeUtils.constructBinaryTree(Arrays.asList(1, 3, 2, 5)), TreeUtils.constructBinaryTree(Arrays.asList(2, 1, 3, null, 4, null, 7))));`
`23`	`25`	`}`
`24`	`26`
	`27`	`+ @Test`
	`28`	`+ public void test2() {`
	`29`	`+ assertEquals(TreeUtils.constructBinaryTree(Arrays.asList(3, 4, 5, 5, 4, null, 7)), solution2.mergeTrees(TreeUtils.constructBinaryTree(Arrays.asList(1, 3, 2, 5)), TreeUtils.constructBinaryTree(Arrays.asList(2, 1, 3, null, 4, null, 7))));`
	`30`	`+ }`
	`31`	`+`
`25`	`32`	`}`