From 7f8225fac8f8e696482e899ea0a6c610dc411e9c Mon Sep 17 00:00:00 2001
From: danzang100 <12danysamuel@gmail.com>
Date: Mon, 17 Mar 2025 22:47:23 +0530
Subject: [PATCH] Solution #199 - Daniel/Edited - 17.03.2025

---
 .../Left and Right View/Explanation.md        | 16 +++++++++++
 .../Left and Right View/Solution.cpp          | 28 +++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 Trees (Binary Trees)/Views of Trees/Left and Right View/Explanation.md
 create mode 100644 Trees (Binary Trees)/Views of Trees/Left and Right View/Solution.cpp

diff --git a/Trees (Binary Trees)/Views of Trees/Left and Right View/Explanation.md b/Trees (Binary Trees)/Views of Trees/Left and Right View/Explanation.md
new file mode 100644
index 0000000..198a3e6
--- /dev/null
+++ b/Trees (Binary Trees)/Views of Trees/Left and Right View/Explanation.md	
@@ -0,0 +1,16 @@
+Left View of tree.
+
+Brute Force Approach:
+
+1. Perform a complete level order traversal of the tree and maintain a matrix of all nodes visited by level.
+2. Choose only the first element for each level and return.
+
+Time Complexity: O(n)
+Space Complexity: O(n)
+
+Optimal Approach:
+
+1. Perform DFS traversal of the tree prioritising the left subtree each time.
+2. Take the first element of each level and return.
+
+For right view, repeat the same but take the last element of the matrix or perform DFS with the right subtree prioritised.
diff --git a/Trees (Binary Trees)/Views of Trees/Left and Right View/Solution.cpp b/Trees (Binary Trees)/Views of Trees/Left and Right View/Solution.cpp
new file mode 100644
index 0000000..13b0724
--- /dev/null
+++ b/Trees (Binary Trees)/Views of Trees/Left and Right View/Solution.cpp	
@@ -0,0 +1,28 @@
+class Solution {
+    public:
+      vector<int> leftView(Node *root) {
+          vector<int> result;
+          traverse(root, 0, result);
+          return result;
+      }
+      void traverse(Node* root, int level, vector<int>& res){
+        //BRUTE FORCE APPROACH
+          if(root == NULL) return;
+          if(res.size() <= level){
+             res.push_back({});
+          }
+          res[level].push_back(root->data);
+          traverse(root->left, level+1, res);
+          traverse(root->right, level+1, res);
+
+          //OPTIMAL APPROACH
+          if(!root) return;
+          
+          if(res.size() == level){
+              res.push_back(root->data);
+          }
+          
+          traverse(root->left, level+1, res);
+          traverse(root->right, level+1, res);
+      }
+  };
\ No newline at end of file