I have the same issue, I am using JAVA. Did you discover the problem? 
Thats my code:
import java.util.*;
public class Main{

    public static void main(String[] argc){
        Scanner input =  new Scanner(System.in);
        String[] str = new String[4];
        char[] chr = new char[26];
        int[] counter = new int[26];
        char chr_temp;

        for(String s: str){
            s = input.nextLine();
            for(int c = 0; c < s.length(); c++){
                chr_temp = s.charAt(c);

                if((chr_temp >= 'A') && (chr_temp <= 'z')){
                    chr[chr_temp-65] = chr_temp;
                    counter[chr_temp - 65]++;
                }

            }
        }
        int max = 0;
        for(int i: counter){
            if(i > max)
                max = i;
        }
        int l =0;
        while (max > 0){
            for(int i: counter){
                l++;
                if(l == 25 && i >= max)
                    System.out.print("*");
                else if(l == 25 && i < max)
                    System.out.print(" ");
                else if(i >= max)
                    System.out.print("* ");
                else System.out.print("  ");
            }
            System.out.println();
            max--;
        }

        for(char c: chr){
            if(c == chr[25])
            System.out.print(c);
            else   System.out.print(c +" ");

        }
System.out.println();


    }
}