Added DFS Algorithm (#199)

* FibonacciSearch

* FibonacciSearch

* Depth First Search Algorithms

* Depth First Search Algorithms

* Depth First Search Algorithms

* Depth First Search Algorithms

Graphs/DFS.js

@@ -0,0 +1,76 @@
+/*
+ * Author: Surendra Kumar
+ * DFS Algorithm implementation in JavaScript
+ * DFS Algorithm for traversing or searching graph data structures.
+*/
+
+function traverseDFS (root) {
+  const stack = [root]
+  const res = []
+
+  while (stack.length) {
+    const curr = stack.pop()
+    res.push(curr.key)
+
+    if (curr.right) {
+      stack.push(curr.right)
+    }
+
+    if (curr.left) {
+      stack.push(curr.left)
+    }
+  }
+
+  return res.reverse()
+}
+
+function searchDFS (tree, value) {
+  var stack = []
+
+  stack.push(tree[0])
+
+  while (stack.length !== 0) {
+    for (let i = 0; i < stack.length; i++) {
+      var node = stack.pop()
+
+      if (node.value === value) {
+        return node
+      }
+      if (node.right) {
+        stack.push(tree[node.right])
+      }
+      if (node.left) {
+        stack.push(tree[node.left])
+      }
+    }
+  }
+  return null
+}
+
+var tree = [
+  { value: 6, left: 1, right: 2 },
+  { value: 5, left: 3, right: 4 },
+  { value: 7, left: null, right: 5 },
+  { value: 3, left: 6, right: null },
+  { value: 4, left: null, right: null },
+  { value: 9, left: 7, right: 8 },
+  { value: 2, left: 9, right: null },
+  { value: 8, left: null, right: null },
+  { value: 10, left: null, right: null },
+  { value: 1, left: null, right: null }
+]
+
+searchDFS(tree, 9)
+searchDFS(tree, 10)
+
+traverseDFS(6)
+
+//            6
+//           / \
+//          5   7
+//         / \   \
+//        3   4   9
+//       /       / \
+//      2       8   10
+//     /
+//    1