Question

How to remove odd frequency characters from a string in Swift

Answer 1

import Foundation

func removeOddFrequencyCharacters(_ s: String) -> String {
    var frequencyMap = [Character: Int]()
    
    // Count the frequency of each character
    for ch in s {
        frequencyMap[ch, default: 0] += 1
    }
    
    // Build the result string excluding characters with odd frequencies
    var result = ""
    for ch in s {
        if frequencyMap[ch]! % 2 == 0 {
            result.append(ch)
        }
    }
    
    return result
}

let s = "swift programming version 6.0.1"

let newString = removeOddFrequencyCharacters(s)

print(newString)



/*
run:

sogmmngson..

*/

 

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