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Total length of string from given Array of strings composed using given characters
• Difficulty Level : Expert
• Last Updated : 28 Aug, 2020

Given a list of characters and an array of strings, find the total length of all strings in the array of strings that can be composed using the given characters.

Examples:

Input: string = [“mouse”, “me”, “bat”, “lion”], chars = “eusamotb”
Output: 10
Explanation:
The strings that can be formed using the characters “eusamotb” are “mouse” and “me” and “bat”.
Length of “mouse” is 5, length of “me” is 2, and length of “bat” is 3
Sum of all lengths = 5 + 2 + 3 = 10.

Input: string = [“hi”, “data”, “geeksforgeeks”], chars = “tiadha”
Output: 6
Explanation:
The strings that can be formed using the characters “tiadha” are “hi” and “data”. Where length of “hi” is 2, length of “data” is 4, the sum of all is 2 + 4 = 6.

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:

To solve the problem mentioned above we have to follow the steps given below:

• We can use characters from the given character string that is ‘chars’ while forming a string. We can also reuse the used characters for forming the next string
• Maintain an unordered map with character as a key and the value by keeping track of the frequency of each character from the string of chars.
• Every time we scan characters from the list of string we reduce the frequency of character from the unordered map but we have to maintain the copy of the original map so as to check the second string .
• If the key is not present in the map it creates one with default value as zero rather than throwing an error.

Below is the implementation of the above approach:

## C++

 `// C++ implementation to find total length ``// of string composed of given characters ``// formed from given Array of strings `` ` `#include  ``using` `namespace` `std; `` ` `// Function to count the total length ``int` `countCharacters( ``    ``vector& strings, ``    ``string chars) ``{ ``    ``int` `res = 0; `` ` `    ``// Unordered_map for ``    ``// keeping frequency of characters ``    ``unordered_map<``char``, ``int``> freq; `` ` `    ``// Calculate the frequency ``    ``for` `(``int` `i = 0; i < chars.length(); i++) ``        ``freq[chars[i]] += 1; `` ` `    ``// Iterate in the N strings ``    ``for` `(``auto` `st : strings) { `` ` `        ``bool` `flag = ``true``; `` ` `        ``// Iterates in the string ``        ``for` `(``auto` `c : st) { `` ` `            ``// Checks if given character of string ``            ``// string appears in it or not ``            ``if` `(!freq) { ``                ``flag = ``false``; ``                ``break``; ``            ``} ``        ``} `` ` `        ``// Adds the length of string ``        ``// if all characters are present ``        ``if` `(flag) ``            ``res += st.length(); ``    ``} `` ` `    ``// Return the final result ``    ``return` `res; ``} `` ` `// Driver code ``int` `main() ``{ ``    ``vector strings ``        ``= { ``"hi"``, ``"data"``, ``            ``"geeksforgeeks"` `}; `` ` `    ``string chars = ``"tiadhae"``; `` ` `    ``cout << countCharacters(strings, chars); `` ` `    ``return` `0; ``} `

## Java

 `// Java implementation to find total length ``// of string composed of given characters ``// formed from given Array of strings ``import` `java.util.*; ``class` `GFG { ``     ` `// Function to count the total length ``static` `int` `countCharacters(List strings, ``                                ``String chars) ``{ ``    ``int` `res = ``0``; `` ` `    ``// Map for ``    ``// keeping frequency of characters ``    ``Map freq = ``new` `HashMap<>(); `` ` `    ``// Calculate the frequency ``    ``for` `(``int` `i = ``0``; i < chars.length(); i++) ``    ``{ ``        ``freq.put(chars.charAt(i), ``        ``freq.getOrDefault(chars.charAt(i), ``0``) + ``1``); ``    ``} `` ` `    ``// Iterate in the N strings ``    ``for` `(String st : strings) ``    ``{ ``        ``boolean` `flag = ``true``; `` ` `        ``// Iterates in the string ``        ``for` `(``char` `c : st.toCharArray()) ``        ``{ `` ` `            ``// Checks if given character of string ``            ``// string appears in it or not ``            ``if` `(!freq.containsKey(c)) ``            ``{ ``                ``flag = ``false``; ``                ``break``; ``            ``} ``        ``} `` ` `        ``// Adds the length of string ``        ``// if all characters are present ``        ``if` `(flag) ``            ``res += st.length(); ``    ``} `` ` `    ``// Return the final result ``    ``return` `res; ``} `` ` `// Driver code ``public` `static` `void` `main(String[] args) ``{ ``    ``List strings = Arrays.asList(``"hi"``, ``"data"``, ``                                        ``"geeksforgeeks"``); `` ` `    ``String chars = ``"tiadhae"``; `` ` `    ``System.out.println(countCharacters(strings, chars)); ``} ``} `` ` `// This code is contributed by offbeat `

## Python3

 `# Python3 implementation to find total length ``# of string composed of given characters ``# formed from given Array of strings `` ` ` ` `# Function to count the total length ``def` `countCharacters(arr, chars): ``    ``res ``=` `0`` ` `    ``# Unordered_map for ``    ``# keeping frequency of characters ``    ``freq ``=` `dict``() `` ` `    ``# Calculate the frequency ``    ``for` `i ``in` `range``(``len``(chars)): ``        ``freq[chars[i]] ``=` `freq.get(chars[i], ``0``)``+``1`` ` `    ``# Iterate in the N strings ``    ``for` `st ``in` `arr: `` ` `        ``flag ``=` `True`` ` `        ``# Iterates in the string ``        ``for` `c ``in` `st: `` ` `            ``# Checks if given character of string ``            ``# string appears in it or not ``            ``if` `(c ``not` `in` `freq): ``                ``flag ``=` `False``                ``break`` ` `        ``# Adds the length of string ``        ``# if all characters are present ``        ``if` `(flag): ``            ``res ``+``=` `len``(st) `` ` `    ``# Return the final result ``    ``return` `res `` ` `# Driver code ``if` `__name__ ``=``=` `'__main__'``: ``    ``arr ``=``[``"hi"``, ``"data"``, ``"geeksforgeeks"``] `` ` `    ``chars ``=` `"tiadhae"`` ` `    ``print``(countCharacters(arr, chars)) `` ` `# This code is contributed by mohit kumar 29 `

## C#

 `// C# implementation to find total length``// of string composed of given characters``// formed from given Array of strings``using` `System;``using` `System.Collections.Generic; ``using` `System.Linq;`` ` `class` `GFG{`` ` `// Function to count the total length``static` `int` `countCharacters(List<``string``> strings, ``                                ``string` `chars)``{``    ``int` `res = 0;``     ` `    ``// Dictionary for keeping frequency``    ``// of characters``    ``Dictionary<``char``,``               ``int``> freq = ``new` `Dictionary<``char``,``                                          ``int``>();``     ` `    ``// Calculate the frequency``    ``for``(``int` `i = 0; i < chars.Length; i++)``    ``{``        ``if``(freq.ContainsKey(chars[i]))``        ``{``            ``freq[chars[i]]++;``        ``}``        ``else``        ``{``            ``freq.Add(chars[i], ``                     ``freq.GetValueOrDefault(``                         ``chars[i], 0) + 1); ``        ``}``    ``}``     ` `    ``// Iterate in the N strings``    ``foreach``(``string` `st ``in` `strings)``    ``{``        ``bool` `flag = ``true``;``         ` `        ``// Iterates in the string``        ``foreach` `(``char` `c ``in` `st.ToCharArray())``        ``{``             ` `            ``// Checks if given character of string``            ``// string appears in it or not``            ``if` `(!freq.ContainsKey(c)) ``            ``{``                ``flag = ``false``;``                ``break``;``            ``}``        ``}``         ` `        ``// Adds the length of string``        ``// if all characters are present``        ``if` `(flag)``            ``res += st.Length;``    ``}``     ` `    ``// Return the final result``    ``return` `res;``}`` ` `// Driver code``public` `static` `void` `Main(``string``[] args)``{``    ``string` `[]tmp = { ``"hi"``, ``"data"``, ``                     ``"geeksforgeeks"` `};``                      ` `    ``List<``string``> strings = tmp.ToList();`` ` `    ``string` `chars = ``"tiadhae"``;`` ` `    ``Console.Write(countCharacters(strings, chars));``}``}`` ` `// This code is contributed by rutvik_56`
Output:
```6
```

Time Complexity: O(n * m), where n is the length of the char and m is the length of the string.

Auxiliary Space Complexity: O(1), as the undordered map will be of size 26 only.

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