# Count the nodes of a tree whose weighted string does not contain any duplicate characters

Given a tree, and the weights (in the form of strings) of all the nodes, the task is to count the nodes whose weights does not contain any duplicate character.

**Examples:**

Input:

Output:2

Only the strings of the node 1 and 4 contains unique strings.

**Approach:** Perform dfs on the tree and for every node, check if it’s string contains duplicate char or not, If not then increment the count.

Below is the implementation of the above approach:

`// C++ implementation of the approach ` `#include <bits/stdc++.h> ` `using` `namespace` `std; ` ` ` `int` `cnt = 0; ` ` ` `vector<` `int` `> graph[100]; ` `vector<string> weight(100); ` ` ` `// Function that returns true if the ` `// string contains unique characters ` `bool` `uniqueChars(string x) ` `{ ` ` ` `map<` `char` `, ` `int` `> mp; ` ` ` `int` `n = x.size(); ` ` ` ` ` `for` `(` `int` `i = 0; i < n; i++) ` ` ` `mp[x[i]]++; ` ` ` `if` `(mp.size() == x.size()) ` ` ` `return` `true` `; ` ` ` `else` ` ` `return` `false` `; ` `} ` ` ` `// Function to perform dfs ` `void` `dfs(` `int` `node, ` `int` `parent) ` `{ ` ` ` `// If weighted string of the current ` ` ` `// node contains unique characters ` ` ` `if` `(uniqueChars(weight[node])) ` ` ` `cnt += 1; ` ` ` ` ` `for` `(` `int` `to : graph[node]) { ` ` ` `if` `(to == parent) ` ` ` `continue` `; ` ` ` `dfs(to, node); ` ` ` `} ` `} ` ` ` `// Driver code ` `int` `main() ` `{ ` ` ` ` ` `// Weights of the nodes ` ` ` `weight[1] = ` `"abc"` `; ` ` ` `weight[2] = ` `"aba"` `; ` ` ` `weight[3] = ` `"bcb"` `; ` ` ` `weight[4] = ` `"moh"` `; ` ` ` `weight[5] = ` `"aa"` `; ` ` ` ` ` `// Edges of the tree ` ` ` `graph[1].push_back(2); ` ` ` `graph[2].push_back(3); ` ` ` `graph[2].push_back(4); ` ` ` `graph[1].push_back(5); ` ` ` ` ` `dfs(1, 1); ` ` ` ` ` `cout << cnt; ` ` ` ` ` `return` `0; ` `} ` |

*chevron_right*

*filter_none*

**Output:**

2

## Recommended Posts:

- Count the nodes of the tree whose weighted string contains a vowel
- Count the nodes of the given tree whose weighted string is a palindrome
- Count the nodes of a tree whose weighted string is an anagram of the given string
- Weighted sum of the characters of a string in an array | Set 2
- Lexicographic rank of a string with duplicate characters
- Count the nodes of the tree which make a pangram when concatenated with the sub-tree nodes
- Count the nodes in the given tree whose weight is even
- Count the nodes in the given tree whose weight is even parity
- Count Non-Leaf nodes in a Binary Tree
- Count the number of nodes at a given level in a tree using DFS
- Count the nodes in the given tree whose weight is prime
- Count the nodes in the given tree whose weight is a power of two
- Count the number of nodes at given level in a tree using BFS.
- Count the nodes in the given tree whose sum of digits of weight is odd
- Determine the count of Leaf nodes in an N-ary tree

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.