From ebd2901fe20da9fddb1ec95b80f6864ec6db0538 Mon Sep 17 00:00:00 2001
From: salonirk11 <salonirk11@gmail.com>
Date: Fri, 18 Oct 2019 21:06:29 +0530
Subject: [PATCH] add vertical tree traversal in cpp

---
 .../Vertical/cpp/vertical_traversal.cpp       | 120 ++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 Tree/Traverals/Vertical/cpp/vertical_traversal.cpp

diff --git a/Tree/Traverals/Vertical/cpp/vertical_traversal.cpp b/Tree/Traverals/Vertical/cpp/vertical_traversal.cpp
new file mode 100644
index 000000000..7f16190f7
--- /dev/null
+++ b/Tree/Traverals/Vertical/cpp/vertical_traversal.cpp
@@ -0,0 +1,120 @@
+// Author: Saloni Rajeev Kumar
+// Date created: October 18, 2019
+
+#include <bits/stdc++.h>
+using namespace std;
+
+struct TreeNode {
+  int val;
+  TreeNode *left;
+  TreeNode *right;
+  TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ };
+
+ class Solution {
+ public:
+   vector<int> verticalTraversal(TreeNode* root) {
+         vector<int> res;
+         if (!root)
+             return res;
+
+         map < int,vector<int> > m;
+         int hd = 0;
+         queue<pair<TreeNode*, int> > que;
+         que.push(make_pair(root, hd));
+
+          while (!que.empty())
+          {
+             pair<TreeNode *,int> temp = que.front();
+             que.pop();
+             hd = temp.second;
+             TreeNode* node = temp.first;
+
+             m[hd].push_back(node->val);
+
+             if (node->left != NULL)
+                 que.push(make_pair(node->left, hd-1));
+             if (node->right != NULL)
+                 que.push(make_pair(node->right, hd+1));
+         }
+
+         map< int,vector<int> > :: iterator it;
+         for (it=m.begin(); it!=m.end(); it++)
+             for (int i=0; i<it->second.size(); ++i)
+                 res.push_back(it->second[i]);
+
+         return res;
+     }
+ };
+
+void trimLeftTrailingSpaces(string &input) {
+    input.erase(input.begin(), find_if(input.begin(), input.end(), [](int ch) {
+        return !isspace(ch);
+    }));
+}
+
+void trimRightTrailingSpaces(string &input) {
+    input.erase(find_if(input.rbegin(), input.rend(), [](int ch) {
+        return !isspace(ch);
+    }).base(), input.end());
+}
+
+TreeNode* stringToTreeNode(string input) {
+    trimLeftTrailingSpaces(input);
+    trimRightTrailingSpaces(input);
+    input = input.substr(1, input.length() - 2);
+    if (!input.size()) {
+        return nullptr;
+    }
+
+    string item;
+    stringstream ss;
+    ss.str(input);
+
+    getline(ss, item, ',');
+    TreeNode* root = new TreeNode(stoi(item));
+    queue<TreeNode*> nodeQueue;
+    nodeQueue.push(root);
+
+    while (true) {
+        TreeNode* node = nodeQueue.front();
+        nodeQueue.pop();
+
+        if (!getline(ss, item, ',')) {
+            break;
+        }
+
+        trimLeftTrailingSpaces(item);
+        if (item != "null") {
+            int leftNumber = stoi(item);
+            node->left = new TreeNode(leftNumber);
+            nodeQueue.push(node->left);
+        }
+
+        if (!getline(ss, item, ',')) {
+            break;
+        }
+
+        trimLeftTrailingSpaces(item);
+        if (item != "null") {
+            int rightNumber = stoi(item);
+            node->right = new TreeNode(rightNumber);
+            nodeQueue.push(node->right);
+        }
+    }
+    return root;
+}
+
+int main() {
+    string line;
+    while (getline(cin, line)) {
+        TreeNode* root = stringToTreeNode(line);
+
+        vector<int> ret = Solution().verticalTraversal(root);
+
+        for(auto val: ret)
+          cout << val << "->";
+        cout<<endl;
+    }
+    return 0;
+}