Check if the frequency of any character is more than half the length of the string

Given a string str, the task is to check if the frequency of any character is more than half the length of the given string. The characters can be lowercase or uppercase alphabets, digits and special characters.

Examples:

Input: str = “AAa*2AAAA”
Output: Yes
The frequency of ‘A’ is more than half the length of the string.

Input: str = “abB@2a”
Output: No

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

Approach: The problem can be easily solved by using a frequency array of length 2⁸ i.e. 256 as there are 256 different characters. Iterate through the string and increase the count of the character by one in the frequency array every time it is encountered. Finally, iterate through the frequency array to check if the frequency of any character is more than half the length of the string.

Below is the implementation of the above approach:

C++

// C++ implementation of the approach 
#include <bits/stdc++.h> 
using namespace std; 
#define MAXN 256 
  
// Function that returns true if the frequency 
// of any character is more than half the 
// length of the string 
bool checkHalfFrequency(string str) 
{ 
  
    // Length of the string 
    int L = str.size(); 
  
    // Initialize a frequency array 
    int fre[MAXN] = { 0 }; 
  
    // Iterate the string and update the 
    // frequency of each of the character 
    for (int i = 0; i < L; i++) 
        fre[str[i]]++; 
  
    // Iterate the frequency array 
    for (int i = 0; i < MAXN; i++) 
  
        // If condition is satisfied 
        if (fre[i] > L / 2) 
            return true; 
  
    return false; 
} 
  
// Driver code 
int main() 
{ 
    string str = "GeeksforGeeks"; 
  
    if (checkHalfFrequency(str)) 
        cout << "Yes"; 
    else
        cout << "No"; 
  
    return 0; 
} 

Java

// Java implementation of the approach 
  
class GFG  
{ 
  
    static int MAXN = 256; 
  
    // Function that returns true if the frequency 
    // of any character is more than half the 
    // length of the string 
    static boolean checkHalfFrequency(String str) 
    { 
  
        // Length of the string 
        int L = str.length(); 
  
        // Initialize a frequency array 
        int fre[] = new int[MAXN]; 
  
        // Iterate the string and update the 
        // frequency of each of the character 
        for (int i = 0; i < L; i++) 
        { 
            fre[str.charAt(i)]++; 
        } 
  
        // Iterate the frequency array 
        for (int i = 0; i < MAXN; i++) // If condition is satisfied 
        { 
            if (fre[i] > L / 2)  
            { 
                return true; 
            } 
        } 
  
        return false; 
    } 
  
    // Driver code 
    public static void main(String[] args) 
    { 
        String str = "GeeksforGeeks"; 
  
        if (checkHalfFrequency(str)) 
        { 
            System.out.println("Yes"); 
        }  
        else
        { 
            System.out.println("No"); 
        } 
    } 
} 
  
/* This code contributed by PrinciRaj1992 */

Python3

# Python3 implementation of the approach 
MAXN = 256
  
# Function that returns true if the frequency 
# of any character is more than half the 
# length of the String 
def checkHalfFrequency(Str): 
  
    # Length of the String 
    L = len(Str) 
  
    # Initialize a frequency array 
    fre = [0 for i in range(MAXN)] 
  
    # Iterate the and update the 
    # frequency of each of the character 
    for i in range(L): 
        fre[ord(Str[i])] += 1
  
    # Iterate the frequency array 
    for i in range(MAXN): 
  
        # If condition is satisfied 
        if (fre[i] > L // 2): 
            return True
  
    return False
  
# Driver code 
Str = "GeeksforGeeks"
  
if (checkHalfFrequency(Str)): 
    print("Yes") 
else: 
    print("No") 
  
# This code is contributed by mohit kumar 

C#

// C# implementation of the approach 
using System; 
  
class GFG 
{ 
  
    static int MAXN = 256; 
  
    // Function that returns true if the frequency 
    // of any character is more than half the 
    // length of the string 
    static bool checkHalfFrequency(string str) 
    { 
  
        // Length of the string 
        int L = str.Length; 
  
        // Initialize a frequency array 
        int[] fre = new int[MAXN]; 
  
        // Iterate the string and update the 
        // frequency of each of the character 
        for (int i = 0; i < L; i++) 
        { 
            fre[str[i]]++; 
        } 
  
        // Iterate the frequency array 
        for (int i = 0; i < MAXN; i++) // If condition is satisfied 
        { 
            if (fre[i] > L / 2)  
            { 
                return true; 
            } 
        } 
  
        return false; 
    } 
  
    // Driver code 
    public static void Main() 
    { 
        string str = "GeeksforGeeks"; 
  
        if (checkHalfFrequency(str)) 
        { 
            Console.WriteLine("Yes"); 
        }  
        else
        { 
            Console.WriteLine("No"); 
        } 
    } 
} 
  
/* This code contributed by Code_Mech */

PHP

<?php 
// PHP implementation of the approach 
      
// Function that returns true if the frequency 
// of any character is more than half the 
// length of the string 
function checkHalfFrequency($str) 
{ 
    $MAXN = 256; 
      
    // Length of the string 
    $L = strlen($str); 
  
    // Initialize a frequency array 
    $fre = array_fill(0, $MAXN, 0 ); 
  
    // Iterate the string and update the 
    // frequency of each of the character 
    for ($i = 0; $i < $L; $i++) 
    { 
        $fre[ord($str[$i])]++; 
    } 
  
    // Iterate the frequency array 
    for ($i = 0; $i < $MAXN; $i++) // If condition is satisfied 
    { 
        if ($fre[$i] > (int)($L / 2))  
        { 
            return true; 
        } 
    } 
  
    return false; 
} 
  
// Driver code 
$str = "GeeksforGeeks"; 
  
if (checkHalfFrequency($str)) 
{ 
    echo("Yes"); 
}  
else
{ 
    echo("No"); 
} 
  
// This code is contributed by Code_Mech 

Output:

No

GeeksforGeeks has prepared a complete interview preparation course with premium videos, theory, practice problems, TA support and many more features. Please refer Placement 100 for details

My Personal Notes

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

C++

Java

Python3

C#

PHP

Recommended Posts: