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

  • Last Updated : 03 Nov, 2021

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 
 

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
Javascript



<script>
 
// Javascript implementation of the approach
var MAXN = 256
 
// Function that returns true if the frequency
// of any character is more than half the
// length of the string
function checkHalfFrequency(str)
{
 
    // Length of the string
    var L = str.length;
 
    // Initialize a frequency array
    var fre = Array(MAXN);
 
    // Iterate the string and update the
    // frequency of each of the character
    for(var i = 0; i < L; i++)
        fre[str[i]]++;
 
    // Iterate the frequency array
    for(var i = 0; i < MAXN; i++)
 
        // If condition is satisfied
        if (fre[i] > L / 2)
            return true;
 
    return false;
}
 
// Driver code
var str = "GeeksforGeeks";
 
if (checkHalfFrequency(str))
    document.write( "Yes");
else
    document.write( "No");
     
// This code is contributed by itsok
 
</script>
Output: 
No
 
Time Complexity: O(N),  N = length of the string
Auxiliary Space: O(1)

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Article Contributed By :
https://media.geeksforgeeks.org/auth/avatar.png
rupesh_rao
@rupesh_rao
Vote for difficulty





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