Count of strings with frequency of each character at most X and length at least Y

Last Updated : 07 Dec, 2021

Given an array arr[] of strings and integers X and Y, the task is to find the count of strings with frequency of each character at most X and length of the string at least Y.

Examples:

Input: arr[] = { "ab", "derdee", "erre" }, X = 2, Y = 4
Output: 1
Explanation: Strings with character frequency at most 2 and
length at least 4 is "erre". Hence count is 1

Input: arr[] = {"ag", "ka", "nanana"}, X = 3, Y = 2
Output: 3

Approach: Follow the approach mentioned below to solve the problem:

Traverse the array of string, and for each string follow the steps below.
Create a frequency map of characters.
Whenever any character has a frequency greater than X, or length less than Y, skip the current string.
If no character has frequency more than X, and length at least Y, increment the count of answer.
Return the count stored in answer when all the strings are traversed.

C++

#include <bits/stdc++.h>
using namespace std;

// Function to check if
// the string has
// frequency of each character
// less than X
bool isValid(string s, int X)
{
    vector<int> freq(26, 0);

    // Loop to check the frequency
    // of each character in the string
    for (char c : s) {
        freq[c - 'a']++;
    }

    // Loop to check
    // if the frequency of all characters
    // are at most X
    for (int i = 0; i < 26; i++)
        if (freq[i] > X)
            return false;
    return true;
}

// Function to calculate the count of strings
int getCount(vector<string>& arr, int X, int Y)
{
    int ans = 0;

    // Loop to iterate the string array
    for (string st : arr) {
        if (isValid(st, X) && st.length() >= Y) {
            ans++;
        }
    }
    return ans;
}

// Driver Code
int main()
{
    vector<string> arr = { "ab", "derdee", "erre" };
    int X = 2, Y = 4;

    // Function call to get count for arr[]
    cout << getCount(arr, X, Y);
    return 0;
}

Java

// Java program for the above approach
import java.util.*;

class GFG 
{

  // Function to check if
  // the string has
  // frequency of each character
  // less than X
  static boolean isValid(String s, int X)
  {
    int freq[] = new int[26];

    // Loop to check the frequency
    // of each character in the string
    for (int i=0;i<s.length();i++) {
      char c = s.charAt(i);
      freq[c - 'a']++;
    }

    // Loop to check
    // if the frequency of all characters
    // are at most X
    for (int i = 0; i < 26; i++)
      if (freq[i] > X)
        return false;
    return true;
  }

  // Function to calculate the count of strings
  static int getCount(String[] arr, int X, int Y)
  {
    int ans = 0;

    // Loop to iterate the string array
    for (String st : arr) {
      if (isValid(st, X) && st.length() >= Y) {
        ans++;
      }
    }
    return ans;
  }

  // Driver Code
  public static void main (String[] args)
  {
    String arr[] = { "ab", "derdee", "erre" };
    int X = 2, Y = 4;

    // Function call to get count for arr[]

    System.out.println(getCount(arr, X, Y));
  }
}

// This code is contributed by Potta Lokesh

Python3

# Function to check if
# the string has
# frequency of each character
# less than X
def isValid (s, X) :
    freq = [0] * 26

    # Loop to check the frequency
    # of each character in the string
    for c in s:
        freq[ord(c)  - ord("a")] += 1
    

    # Loop to check
    # if the frequency of all characters
    # are at most X
    for i in range(26):
        if (freq[i] > X):
            return False
    return True


# Function to calculate the count of strings
def getCount (arr, X, Y):
    ans = 0

    # Loop to iterate the string array
    for st in arr:
        if (isValid(st, X) and len(st) >= Y):
            ans += 1
    return ans


# Driver Code

arr = ["ab", "derdee", "erre"]
X = 2
Y = 4

# Function call to get count for arr[]
print(getCount(arr, X, Y))

# This code is contributed by gfgking.

// C# program for the above approach
using System;

class GFG{

// Function to check if the string
// has frequency of each character
// less than X
static bool isValid(String s, int X)
{
    int []freq = new int[26];
    
    // Loop to check the frequency
    // of each character in the string
    for(int i = 0; i < s.Length; i++)
    {
        char c = s[i];
        freq[c - 'a']++;
    }
    
    // Loop to check if the frequency 
    // of all characters are at most X
    for(int i = 0; i < 26; i++)
        if (freq[i] > X)
            return false;
            
        return true;
}

// Function to calculate the count of strings
static int getCount(String[] arr, int X, int Y)
{
    int ans = 0;
    
    // Loop to iterate the string array
    foreach (String st in arr)
    {
        if (isValid(st, X) && st.Length >= Y)
        {
            ans++;
        }
    }
    return ans;
}

// Driver Code
public static void Main(String[] args)
{
    String []arr = { "ab", "derdee", "erre" };
    int X = 2, Y = 4;
    
    // Function call to get count for []arr
    Console.WriteLine(getCount(arr, X, Y));
}
}

// This code is contributed by shikhasingrajput

JavaScript

<script>

    // Function to check if
    // the string has
    // frequency of each character
    // less than X
    const isValid = (s, X) => {
        let freq = new Array(26).fill(0);

        // Loop to check the frequency
        // of each character in the string
        for (let c in s) {
            freq[s.charCodeAt(c) - "a".charCodeAt(0)]++;
        }

        // Loop to check
        // if the frequency of all characters
        // are at most X
        for (let i = 0; i < 26; i++)
            if (freq[i] > X)
                return false;
        return true;
    }

    // Function to calculate the count of strings
    const getCount = (arr, X, Y) => {
        let ans = 0;

        // Loop to iterate the string array
        for (let st in arr) {
            if (isValid(arr[st], X) && arr[st].length >= Y) {
                ans++;
            }
        }
        return ans;
    }

    // Driver Code

    let arr = ["ab", "derdee", "erre"];
    let X = 2, Y = 4;

    // Function call to get count for arr[]
    document.write(getCount(arr, X, Y));

    // This code is contributed by rakeshsahni

</script>