Same Tree - Iterative

dksifoua · Sep 10, 2024 · 9944b5e · 9944b5e
1 parent 4d5c374
commit 9944b5e
Show file tree

Hide file tree

Showing 2 changed files with 31 additions and 0 deletions.
diff --git a/src/main/java/io/dksifoua/leetcode/sameTree/Solution.java b/src/main/java/io/dksifoua/leetcode/sameTree/Solution.java
@@ -2,6 +2,9 @@
 
 import io.dksifoua.leetcode.utils.TreeNode;
 
+import java.util.LinkedList;
+import java.util.Queue;
+
 public class Solution {
 
     public boolean isSameTree(TreeNode p, TreeNode q) {
@@ -12,4 +15,22 @@ public boolean isSameTree(TreeNode p, TreeNode q) {
                 && this.isSameTree(p.getLeft(), q.getLeft())
                 && this.isSameTree(p.getRight(), q.getRight());
     }
+
+    public boolean isSameTreeIterative(TreeNode p, TreeNode q) {
+        Queue<TreeNode> pQueue = new LinkedList<>() {{ add(p); }};
+        Queue<TreeNode> qQueue = new LinkedList<>() {{ add(q); }};
+        while (!pQueue.isEmpty() && !qQueue.isEmpty()) {
+            TreeNode _p = pQueue.poll(), _q = qQueue.poll();
+            if (_p == null && _q == null) continue;
+            if (_p == null || _q == null || _p.getValue() != _q.getValue()) return false;
+
+            pQueue.add(_p.getLeft());
+            qQueue.add(_q.getLeft());
+
+            pQueue.add(_p.getRight());
+            qQueue.add(_q.getRight());
+        }
+
+        return true;
+    }
 }
diff --git a/src/test/java/io/dksifoua/leetcode/sameTree/SolutionTest.java b/src/test/java/io/dksifoua/leetcode/sameTree/SolutionTest.java
@@ -14,9 +14,19 @@ void test1() {
         assertTrue(solution.isSameTree(TreeNode.build(new Integer[] { 1, 2, 3 }), TreeNode.build(new Integer[] { 1, 2, 3 })));
     }
 
+    @Test
+    void test1Iterative() {
+        assertTrue(solution.isSameTreeIterative(TreeNode.build(new Integer[] { 1, 2, 3 }), TreeNode.build(new Integer[] { 1, 2, 3 })));
+    }
+
     @Test
     void test2() {
         assertFalse(solution.isSameTree(TreeNode.build(new Integer[] { 1, 2 }), TreeNode.build(new Integer[] { 1, null, 2 })));
     }
 
+    @Test
+    void test2Iterative() {
+        assertFalse(solution.isSameTreeIterative(TreeNode.build(new Integer[] { 1, 2 }), TreeNode.build(new Integer[] { 1, null, 2 })));
+    }
+
 }