Add solution 116.

Author: javadev

src/Algorithms/0116.populating-next-right-pointers-in-each-node/populating-next-right-pointers-in-each-node.php

@@ -0,0 +1,44 @@
+/*
+// Definition for a Node.
+class Node {
+    public $val;
+    public $left;
+    public $right;
+    public $next;
+
+    @param Integer $val 
+    @param Node $left 
+    @param Node $right 
+    @param Node $next 
+    function __construct($val, $left, $right, $next) {
+        $this->val = $val;
+        $this->left = $left;
+        $this->right = $right;
+        $this->next = $next;
+    }
+}
+*/
+class Solution {
+
+    /**
+     * @param Node $root
+     * @return Node
+     */
+    function connect($root) {
+        if($root==null){
+            return null;
+        }     
+        
+        if($root->left!=null && $root->right!=null){
+            $root->left->next = $root->right;
+        }
+        
+        if($root->next!=null && $root->right!=null){
+            $root->right->next=$root->next->left;
+        }
+        
+        self::connect($root->left);
+        self::connect($root->right);
+        return $root;
+    }
+}