# Count of strings that does not contain any character of a given string

• Last Updated : 23 Dec, 2021

Given an array arr containing N strings and a string str, the task is to find the number of strings that do not contain any character of string str.

Examples:

Input: arr[] = {“abcd”, “hijk”, “xyz”, “ayt”}, str=”apple”
Output: 2
Explanation: “hijk” and “xyz” are the strings that do not contain any character of str

Input: arr[] = {“apple”, “banana”, “pear”}, str=”nil”
Output: 1

Approach: Follow the below steps to solve this problem:

1. Create a set st and store each character of string str in this set.
2. Create a variable ans to store the number of all the required strings.
3. Now, start traversing on the array and for each string, check if any of its character is present in the set st or not. If it is, then this is not a required string.
4. If it doesn’t contain any character from the set, increase answer by 1.
5. Return ans after the loop ends, as the answer to this problem.

Below is the implementation of the above approach:

## C++

 `// C++ code for the above approach` `#include ``using` `namespace` `std;` `// Function to count the number of strings``// that does not contain any character of string str``int` `allowedStrings(vector& arr, string str)``{``    ``int` `ans = 0;``    ``unordered_set<``char``> st;``    ``for` `(``auto` `x : str) {``        ``st.insert(x);``    ``}` `    ``for` `(``auto` `x : arr) {``        ``bool` `allowed = 1;``        ``for` `(``auto` `y : x) {` `            ``// If the character is present in st``            ``if` `(st.find(y) != st.end()) {``                ``allowed = 0;``                ``break``;``            ``}``        ``}` `        ``// If the string doesn't``        ``// have any character of st``        ``if` `(allowed) {``            ``ans += 1;``        ``}``    ``}` `    ``return` `ans;``}` `// Driver Code``int` `main()``{``    ``vector arr``        ``= { ``"abcd"``, ``"hijk"``, ``"xyz"``, ``"ayt"` `};``    ``string str = ``"apple"``;``    ``cout << allowedStrings(arr, str);``}`

## Python3

 `# Python 3 code for the above approach` `# Function to count the number of strings``# that does not contain any character of string str``def` `allowedStrings(arr, st):``    ``ans ``=` `0``    ``st1 ``=` `set``([])``    ``for` `x ``in` `st:``        ``st1.add(x)` `    ``for` `x ``in` `arr:``        ``allowed ``=` `1``        ``for` `y ``in` `x:` `            ``# If the character is present in st1``            ``if` `(y ``in` `st1):``                ``allowed ``=` `0``                ``break` `        ``# If the string doesn't``        ``# have any character of st``        ``if` `(allowed):``            ``ans ``+``=` `1` `    ``return` `ans` `# Driver Code``if` `__name__ ``=``=` `"__main__"``:` `    ``arr ``=` `[``"abcd"``, ``"hijk"``, ``"xyz"``, ``"ayt"``]``    ``st ``=` `"apple"``    ``print``(allowedStrings(arr, st))` `    ``# This code is contributed by ukasp.`

## Javascript

 ``

Output
`2`

Time Complexity: O(N*M), where N is the size of the array and M is the size of the longest string.
Auxiliary Space: O(N)

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