HackerRank Sherlock and the Valid String problem solution

In this HackerRank Sherlock and the Valid String Interview preparation kit problem, You need to complete the isValid function.

Problem solution in Python programming.

#!/bin/python3

import math
import os
import random
import re
import sys
from collections import Counter

# Complete the isValid function below.
def isValid(s):
    d = Counter(s)
    counts = Counter(d.values())
    if len(counts) == 1:
        return "YES"
    elif len(counts) > 2:
        return "NO"
    else:
        max_v = max(counts.values())
        k1, k2 = counts.keys()
        if (max_v == len(d) - 1):
            if (abs(k1 - k2) == 1):
                return "YES"
            elif (min(k1, k2) == 1):
                if counts[1] == 1:
                    return "YES"
                else:
                    return "NO"
            else:
                return "NO"
        else:
            return "NO"

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    s = input()

    result = isValid(s)

    fptr.write(result + '\n')

    fptr.close()

Problem solution in Java Programming.

import java.io.*;
import java.util.*;
import java.math.BigInteger;
import java.util.Map.Entry;

import static java.lang.Math.*;

public class Solution extends PrintWriter {

	boolean solve() {

		char[] str = nextLine().toCharArray();

		int m = 256, n = str.length + 1;
		int[] cnt = new int[m];
		for (char c : str) {
			++cnt[c];
		}

		int[] f = new int[n];

		for (int val : cnt) {
			++f[val];
		}

		int x = 0;
		for (int i = 1; i < n; i++) {
			if (f[i] > 0) {
				++x;
			}
		}

		if (x == 1) {
			return true;
		}

		if (x > 2) {
			return false;
		}

		int y = 0;

		for (int i = 2; i < n; i++) {
			if (f[i] > 0) {
				++y;
			}
		}

		if (y == 1 && f[1] == 1) {
			return true;
		}

		int z = 0;

		for (int i = 2; i < n; i++) {
			if (f[i] == 1 && f[i - 1] > 0) {
				++z;
			}
		}

		return z == 1;
	}

	void run() {
		println(solve() ? "YES" : "NO");
	}

	int[][] nextMatrix(int n, int m) {
		int[][] matrix = new int[n][m];
		for (int i = 0; i < n; i++)
			for (int j = 0; j < m; j++)
				matrix[i][j] = nextInt();
		return matrix;
	}

	String next() {
		while (!tokenizer.hasMoreTokens())
			tokenizer = new StringTokenizer(nextLine());
		return tokenizer.nextToken();
	}

	boolean hasNext() {
		while (!tokenizer.hasMoreTokens()) {
			String line = nextLine();
			if (line == null) {
				return false;
			}
			tokenizer = new StringTokenizer(line);
		}
		return true;
	}

	int[] nextArray(int n) {
		int[] array = new int[n];
		for (int i = 0; i < n; i++) {
			array[i] = nextInt();
		}
		return array;
	}

	int nextInt() {
		return Integer.parseInt(next());
	}

	long nextLong() {
		return Long.parseLong(next());
	}

	double nextDouble() {
		return Double.parseDouble(next());
	}

	String nextLine() {
		try {
			return reader.readLine();
		} catch (IOException err) {
			return null;
		}
	}

	public Solution(OutputStream outputStream) {
		super(outputStream);
	}

	static BufferedReader reader;
	static StringTokenizer tokenizer = new StringTokenizer("");
	static Random rnd = new Random();

	public static void main(String[] args) throws IOException {
		Solution solution = new Solution(System.out);
		reader = new BufferedReader(new InputStreamReader(System.in));
		solution.run();
		solution.close();
		reader.close();

	}
}

Problem solution in C++ programming.

#include <bits/stdc++.h>

using namespace std;

char s[1234567];

int main() {
  scanf("%s", s);
  int n = strlen(s);
  vector <int> cnt(26, 0);
  for (int i = 0; i < n; i++) {
    cnt[s[i] - 'a']++;
  }
  for (int i = 0; i <= 26; i++) {
    if (cnt[i] == 0) {
      continue;
    }
    if (i < 26) {
      cnt[i]--;
    }
    vector <int> a = cnt;
    sort(a.begin(), a.end());
    int res = a[25];
    bool ok = true;
    for (int j = 0; j < 26; j++) {
      if (a[j] != 0 && a[j] != res) {
        ok = false;
        break;
      }
    }
    if (ok) {
      puts("YES");
      return 0;
    }
    if (i < 26) {
      cnt[i]++;
    }
  }
  puts("NO");
  return 0;
}

Problem solution in C programming.

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int test(int *alphabet)
{
	int num = alphabet[0];
	int i;
	
	for(i = 1; i < 26; i++)
	{
	    if(alphabet[i] == num)
		{
			num = alphabet[i];
		}
		else if(alphabet[i] != num && alphabet[i] != 0)
			return 0;
	}
	return 1;
}


int main() {

	int i = 0;
	int alphabet[26];
	int c = EOF;
	int num, pass = 0;
	
	for(i = 0; i < 26; i++)
		alphabet[i] = 0;
	

	while (( c = getchar() ) != '\n' && c != EOF)
    {
        alphabet[c - '0' - 49]++;
    }

    if(test(alphabet))	
		printf("YES\n");	
	else
	{
		for(i = 0; i < 26; i++)
		{
			if(i != 0)
				alphabet[i - 1]++;
	    	alphabet[i]--;
			if(test(alphabet))
			{
				printf("YES\n");
			    pass = 1;
				break;
			}
		}
		if(pass == 0)
			printf("NO\n");
	}

	return 0;
}

Problem solution in JavaScript programming.

function countHighest(high, array){
    var i = 0,
        counter = 0;

    for (i = 0; i < array.length; i++){
        if (array[i] === high){
            counter++;
        }
    }
    
    return counter;
}

function countLowest(low, array){
    var i = 0,
        counter = 0;

    for (i = 0; i < array.length; i++){
        if (array[i] === low){
            counter++;
        }
    }
    
    return counter;
}

function getLowestValue(alphaArr){
    var i = 0,
        low = -1;
    
    for (i = 0; i < alphaArr.length; i++){
        if (alphaArr[i] !== 0) {
            
           if (low === -1){
               low = alphaArr[i];
           } else if (low > alphaArr[i] ){
               low = alphaArr[i];
           }    
        }
    }
    
    return low;
}

function getHighestValue(alphaArr){
    var i = 0,
        high = 0;
    for (i = 0; i < alphaArr.length; i++){
        if (high < alphaArr[i]){
            high = alphaArr[i];
        }
    }
    
    return high;
}

function createAlphaArray(string){
    var i = 0,
        alphaArr = [];
    
    for (i = 0; i < 26; i++){
        alphaArr.push(0);
    }
    
    for (i = 0; i < string.length; i++){
        alphaArr[string.charCodeAt(i) - 97]++;
    }
    
    return alphaArr;
}

function processData(input) {
    var string = '',
        alpha = [],
        high = 0, low = 0,
        numberOfHighs = 0, numberOfLows = 0;
    
    string = input.split('\n')[0];
    alpha = createAlphaArray(string);
    high = getHighestValue(alpha);
    low = getLowestValue(alpha);
    
   // console.log(alpha);
    
    // if the difference of high and low is greater than or equal to 2,
    // string immediately fails
    if (high - low >= 2){
        if (low === 1 && countLowest(low, alpha) === 1){
            console.log('YES');
        } else {
            console.log('NO');
        }
    } else if (high === low){
        console.log('YES');
    } else {
        numberOfHighs = countHighest(high, alpha);
        numberOfLows = countLowest(low, alpha);
        
        // if we have more highs than lows, we must check number of lows
        if (numberOfHighs > numberOfLows){
            if (numberOfLows === 1){
                console.log('YES');
            } else {
                console.log('NO');
            }
        } else if (numberOfLows > numberOfHighs){
            if (numberOfHighs === 1){
                console.log('YES');
            } else {
                console.log('NO');
            }
        } else if (numberOfLows === numberOfHighs){
            if (numberOfHighs === 1){
                console.log('YES');
            }
            else {
                console.log('NO');
            }
        }
    }
    
    //nsole.log('Highest: ' + high + ' | Lowest: ' + low);
} 

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});