Added a folder for DSA in Kotlin

DSA Kotlin/SquareRoot.kt

@@ -0,0 +1,25 @@
+class Solution {
+    fun mySqrt(x: Int): Int {
+        var s : Long  = 0
+        var e : Long = x.toLong()
+
+        var mid : Long = s + (e-s)/2
+        var res : Long = 0
+
+        while(s<=e){
+
+            if(mid*mid == x.toLong())         
+            return mid.toInt()
+            else if(mid*mid > x.toLong())
+            e = mid - 1
+            else{
+                res = mid;
+                s = mid + 1
+            }
+
+            mid = s + (e-s)/2
+        }
+
+        return res.toInt()
+    }
+}

DSA Kotlin/Tree Traversals/inOrderTraversal.kt

@@ -0,0 +1,29 @@
+/**
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+class Solution {
+    fun Inorder(root: TreeNode?,list: MutableList<Int>){
+
+        if(root==null)
+        return;
+
+        Inorder(root.left,list)
+        list.add(root.`val`)
+        Inorder(root.right,list)
+
+        return;
+    }
+    fun inorderTraversal(root: TreeNode?): List<Int> {
+
+        val ans = mutableListOf<Int>()
+        Inorder(root,ans)
+        return ans
+    }
+}

DSA Kotlin/Tree Traversals/postOrderTraversal.kt

@@ -0,0 +1,30 @@
+/**
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+class Solution {
+    fun Postorder(root: TreeNode?,ans: MutableList<Int>){
+
+        if(root==null)
+        return
+
+        Postorder(root.left,ans)
+        Postorder(root.right,ans)
+        ans.add(root.`val`)
+
+        return
+    }
+    fun postorderTraversal(root: TreeNode?): List<Int> {
+
+        val ans = mutableListOf<Int>()
+        Postorder(root,ans)
+        return ans
+
+    }
+}

DSA Kotlin/Tree Traversals/preOrderTraversal.kt

@@ -0,0 +1,30 @@
+/**
+ * Example:
+ * var ti = TreeNode(5)
+ * var v = ti.`val`
+ * Definition for a binary tree node.
+ * class TreeNode(var `val`: Int) {
+ *     var left: TreeNode? = null
+ *     var right: TreeNode? = null
+ * }
+ */
+class Solution {
+    fun Preorder(root: TreeNode?,list: MutableList<Int>){
+
+        if(root==null)
+        return
+
+        list.add(root.`val`)
+        Preorder(root.left,list)
+        Preorder(root.right,list)
+
+        return
+    }
+    fun preorderTraversal(root: TreeNode?): List<Int> {
+
+        val ans = mutableListOf<Int>()
+        Preorder(root,ans)
+        return ans
+
+    }
+}

DSA Kotlin/palindrome_number.kt

@@ -0,0 +1,16 @@
+class Solution {
+    fun isPalindrome(x: Int): Boolean {
+        var num = x.toString()
+        var check = true
+
+        for(i in 0..((num.length-1)/2)){
+            if(num[i]!=num[num.length-1-i])
+            {
+                check = false
+                break;
+            }
+        }
+
+        return check
+    }
+}