/**

Author: paurush11

Data Structures/Trees/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.cpp

@@ -0,0 +1,34 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+    TreeNode* buildTree(vector<int>& preorder, vector<int>& inorder) {
+        int pre = 0;
+        return maketree(pre,0,preorder.size()-1,inorder,preorder);
+    }
+
+    TreeNode* maketree(int &pre, int start, int end,vector<int>& inorder, vector<int>& postorder){
+        if(start>end || pre>postorder.size())return NULL;
+    TreeNode* root = new TreeNode(postorder[pre]);
+    int index = -1;
+    for(int i = start;i<=end;i++){
+        if(inorder[i] == postorder[pre]){
+            index = i;
+            break;
+        }
+    }
+    pre++;
+    root->left = maketree(pre,start, index-1,inorder,postorder);
+    root->right = maketree(pre,index+1, end,inorder,postorder);
+    return root;
+    }
+};