Update 105_Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.cpp

Author: xliu45

C/105_Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.cpp

@@ -16,43 +16,43 @@ using namespace std;
 
 //  Definition for a binary tree node.
 struct TreeNode {
-	int val;
-	TreeNode *left;
-	TreeNode *right;
-	TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+    int val;
+    TreeNode *left;
+    TreeNode *right;
+    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 };
 
 class Solution {
 public:
-	TreeNode* buildTree(vector<int>& preorder, vector<int>& inorder) {
-		return subtree(preorder, 0, preorder.size() - 1 , inorder, 0, preorder.size() - 1);
-	}
-	TreeNode* subtree(vector<int>& preorder, int begin1, int end1, vector<int>& inorder, int begin2, int end2){
-		int i;
-		if(end1 < begin1)
-			return NULL;
-		if(end1 == begin1)
-			return new TreeNode(preorder.at(begin1));
-
-		TreeNode* root = new TreeNode(preorder.at(begin1));
-		for(i = begin2; i < end2; i++){
-			if(inorder.at(i) == root->val)
-				break;
-		}
-		int left_length = i - begin2;
-		root->left = subtree(preorder, begin1 + 1, begin1 + left_length, inorder, begin2, begin2 + left_length - 1);
-		root->right = subtree(preorder, begin1 + left_length + 1, end1, inorder, begin2 + left_length + 1, end2);
-		return root;
+    TreeNode* buildTree(vector<int>& preorder, vector<int>& inorder) {
+        return subtree(preorder, 0, preorder.size() - 1 , inorder, 0, preorder.size() - 1);
+    }
+    TreeNode* subtree(vector<int>& preorder, int begin1, int end1, vector<int>& inorder, int begin2, int end2){
+	int i;
+	if(end1 < begin1)
+	    return NULL;
+	if(end1 == begin1)
+	    return new TreeNode(preorder.at(begin1));
+
+	TreeNode* root = new TreeNode(preorder.at(begin1));
+	for(i = begin2; i < end2; i++){
+	    if(inorder.at(i) == root->val)
+	        break;
 	}
+	    int left_length = i - begin2;
+	    root->left = subtree(preorder, begin1 + 1, begin1 + left_length, inorder, begin2, begin2 + left_length - 1);
+	    root->right = subtree(preorder, begin1 + left_length + 1, end1, inorder, begin2 + left_length + 1, end2);
+	    return root;
+    }
 };
 
 void main(){
 
-	int pre[] = {1,2,3,4};
-	vector<int> preorder(pre, pre + sizeof(pre) / sizeof(int));
-	int in[] = {2,1,4,3};
-	vector<int> inorder(in, in + sizeof(in) / sizeof(int));
-	Solution sol;
-	TreeNode* root = sol.buildTree(preorder, inorder);
+    int pre[] = {1,2,3,4};
+    vector<int> preorder(pre, pre + sizeof(pre) / sizeof(int));
+    int in[] = {2,1,4,3};
+    vector<int> inorder(in, in + sizeof(in) / sizeof(int));
+    Solution sol;
+    TreeNode* root = sol.buildTree(preorder, inorder);
 
 }