Skip to content
Programming101
Programmingoneonone

Learn everything about programming

  • Home
  • CS Subjects
    • IoT – Internet of Things
    • Digital Communication
    • Human Values
  • Programming Tutorials
    • C Programming
    • Data structures and Algorithms
    • 100+ Java Programs
    • 100+ C Programs
  • HackerRank Solutions
    • HackerRank Algorithms Solutions
    • HackerRank C problems solutions
    • HackerRank C++ problems solutions
    • HackerRank Java problems solutions
    • HackerRank Python problems solutions
Programming101
Programmingoneonone

Learn everything about programming

Leetcode Binary Tree Paths problem solution

YASH PAL, 31 July 2024

In this Leetcode Binary Tree Paths problem solution we have given the root of a binary tree, return all root-to-leaf paths in any order. A leaf is a node with no children.

Leetcode Binary Tree Paths problem solution

Topics we are covering

Toggle
  • Problem solution in Python.
  • Problem solution in Java.
  • Problem solution in C++.
  • Problem solution in C.

Problem solution in Python.

class Solution:
    def binaryTreePaths(self, root: TreeNode) -> List[str]:
        if root is None:
            return []
        path = str(root.val)
        res = []
        self.traverse(root,path,res)
        return res
    
    def traverse(self, root, path, res):
        if root.left is None and root.right is None:
            res.append(path)
        if root.left is not None:
            self.traverse(root.left, path+"->"+str(root.left.val), res)
        if root.right is not None:
            self.traverse(root.right, path+"->"+str(root.right.val), res)

Problem solution in Java.

public class Solution {
public List<String> binaryTreePaths(TreeNode root) {
    List<String> list = new ArrayList<String>();
    if(root == null)  return list;
    StringBuilder str = new StringBuilder();
    binaryHelper(root,list,str);
    return list;
}

private void binaryHelper(TreeNode root, List<String> list, StringBuilder str){
    if(root == null) return;
    StringBuilder newStr = new StringBuilder(str);
    if(newStr.length() != 0)
        newStr.append("->");
    newStr.append(root.val);
    if(root.left == null && root.right == null)
    {
        list.add(newStr.toString());
        return;
    }
        binaryHelper(root.left,list,newStr);
        binaryHelper(root.right,list,newStr);
}
}

Problem solution in C++.

vector<string> binaryTreePaths(TreeNode* root) 
    {
        if(root==NULL) return {};
        else
        {
            vector<string> lefty= binaryTreePaths(root->left);
            vector<string> righty= binaryTreePaths(root->right);
            vector<string> ans;
            string rooty=to_string(root->val);
            int l=lefty.size(), r=righty.size();
            if(l==0 and r==0) 
            {
                vector<string> v;
                v.push_back(rooty);
                return v;
            }
            for(int i=0;i<l;i++)
            {
                string s=rooty+"->"+lefty[i];
                ans.push_back(s);
            }
             for(int i=0;i<r;i++)
            {
                string s=rooty+"->"+righty[i];
                ans.push_back(s);
            }
            return ans;
        }
    }

Problem solution in C.

#define MAX_SIZE 1000

void pre_order_str(struct TreeNode *root, char ***res, int *res_size, char str[]) {
  
  if(NULL == root)
    return;

  char buf[MAX_SIZE];
  int append_size = 0;
  snprintf(buf, MAX_SIZE, "%d", root->val);
  append_size = strlen(buf);
  if(strnlen(str, MAX_SIZE) >= 1) {
    strncat(str, "->", MAX_SIZE);
    append_size += 2;
  }
  strncat(str, buf,MAX_SIZE);
  
  pre_order_str(root->left, res, res_size, str);
  pre_order_str(root->right, res, res_size, str);
  
  /*If leaf */
  if((!root->left) && (!root->right)) {    
    (*res_size)++;
    (*res) = realloc((*res), sizeof(char *) * (*res_size));
    int size = (*res_size) - 1;

    (*res)[size] = malloc(sizeof(char) * MAX_SIZE);
    strncpy((*res)[size], str, MAX_SIZE);
  }  
  
  /* when done with node remove ->val from str */
  str[strnlen(str, MAX_SIZE) - append_size] = '';  
}

char** binaryTreePaths(struct TreeNode* root, int* returnSize) {
  
  char **result = malloc(sizeof(char *) * 1);
  if(NULL == result) {
    *returnSize = 0;
    return NULL;
  }
  
  char str[MAX_SIZE];
  str[0] = '';
  
  pre_order_str(root, &result, returnSize, str);
  
  return result;
  
}

coding problems solutions

Post navigation

Previous post
Next post
  • Automating Image Format Conversion with Python: A Complete Guide
  • HackerRank Separate the Numbers solution
  • How AI Is Revolutionizing Personalized Learning in Schools
  • GTA 5 is the Game of the Year for 2024 and 2025
  • Hackerrank Day 5 loops 30 days of code solution
How to download udemy paid courses for free

Pages

  • About US
  • Contact US
  • Privacy Policy

Programing Practice

  • C Programs
  • java Programs

HackerRank Solutions

  • C
  • C++
  • Java
  • Python
  • Algorithm

Other

  • Leetcode Solutions
  • Interview Preparation

Programming Tutorials

  • DSA
  • C

CS Subjects

  • Digital Communication
  • Human Values
  • Internet Of Things
  • YouTube
  • LinkedIn
  • Facebook
  • Pinterest
  • Instagram
©2025 Programmingoneonone | WordPress Theme by SuperbThemes