Added code for Merge Two Binary Trees, Range Sum of BST and Mirror Re…

…flection Leetcode Problems

Added code for Merge Two Binary Trees, Range Sum of BST and Mirror Reflection Leetcode Problems

leetcode/MergeTwoBinaryTrees.java

@@ -0,0 +1,21 @@
+class MergeTwoBinaryTrees {
+    //TreeNode merge = new TreeNode();
+    public TreeNode mergeTrees(TreeNode root1, TreeNode root2) {
+        if (root1==null) return root2;
+        if (root2==null) return root1;
+        if (root1==null && root2==null) return root1;
+
+        bfs(root1,root2);
+        return root1;
+    }
+    public void bfs(TreeNode root1, TreeNode root2)
+    {
+        if (root1==null || root2==null) return;
+        if (root2.left!=null && root1.left==null) root1.left= root2.left;
+        if (root2.right!=null && root1.right==null) root1.right = root2.right;
+        if (root1!=null && root2!=root1) root1.val = root1.val + root2.val;
+
+        bfs(root1.left,root2.left);
+        bfs(root1.right,root2.right);
+    }
+}

leetcode/MirrorReflection.java

@@ -0,0 +1,28 @@
+class mirrorReflection {
+    public int mirrorReflection(int p, int q) {
+        if (q==0) return 0;
+        int lcm = (p*q)/gcd(p, q);
+        int m = lcm/p;
+        int n = lcm/q;
+        if(m%2==0 && n%2==1) return 0;
+        if(m%2==1 && n%2==1) return 1;
+        if(m%2==1 && n%2==0) return 2;
+        return 0;
+    }
+
+    public int gcd(int a,int b)
+    {
+        if (a==b) return a;
+        if (a<=0) return b;
+        if (b<=0) return a;
+
+        if (a<b)
+        {
+            return gcd(b-a,a);
+        }
+        else
+        {
+            return gcd(a-b,b);
+        }
+    }
+}

leetcode/RangeSumBST.java

@@ -0,0 +1,16 @@
+class RangeSumBST {
+    int sum=0;
+    public int rangeSumBST(TreeNode root, int low, int high) {
+        bfs(root,low,high);
+        return sum;
+    }
+
+    public void bfs(TreeNode root,int low, int high)
+    {
+        if (root==null) return;
+        if (low<=root.val && root.val<=high) sum+=root.val;
+
+        bfs(root.left,low,high);
+        bfs(root.right,low,high);
+    }
+}