Extra Characters Inserted Into Array - c++

Question

I'm a C++ beginner and wrote a program to check if two phrases are anagrams. The characters are being read one at a time and stored in an array. I have everything working, except in some cases, extra characters are being inserted into the array.
For example, if I enter the phrases aabb and abba, this is the output of the program:
Enter two lines that might be anagrams:
--> aabb
--> abba
String A is aabb
String B is abbai?
The two strings are NOT anagrams.
They should be anagrams, but for some reason, i? is added into the array, causing the phrases to not be anagrams. I'm probably overlooking a simple mistake in the code, but would really appreciate any feedback.
Here is the code:
#include <string>
#include <algorithm>
#include <iostream>
using namespace std;
int check_anagram(char [], char []);
int main()
{
char ch, a[60], b[60];
int flag, i;
cout << "Enter two lines that might be anagrams:" << endl;
cout << "--> ";
cin.get(ch);
ch = tolower(ch);
i = 0;
while (ch != '\n')
{
if (ch > '#') {
a[i] = ch;
i++;
}
cin.get(ch);
ch = tolower(ch);
}
cout << "--> ";
cin.get(ch);
ch = tolower(ch);
i = 0;
while (ch != '\n')
{
if (ch > '#') {
b[i] = ch;
i++;
}
cin.get(ch);
ch = tolower(ch);
}
flag = check_anagram(a, b);
cout << "String A is " << a << endl;
cout << "String B is " << b << endl;
cout << "The two strings ";
if (flag == 1)
cout << "ARE";
else
cout << "are NOT";
cout << " anagrams." << endl << endl;
return 0;
}
int check_anagram(char a[], char b[])
{
int first[26] = {0}, second[26] = {0}, c = 0;
while (a[c] != '\0')
{
first[a[c]-'a']++;
c++;
}
c = 0;
while (b[c] != '\0')
{
second[b[c]-'a']++;
c++;
}
for (c = 0; c < 26; c++)
{
if (first[c] != second[c])
return 0;
}
return 1;
}
Thanks in advance!

Answer 1

You just need to terminate the two character arrays with '\0' because the logic in check_anagram treats both arrays as NULL-terminated.
..
while (ch != '\n')
{
if (ch > '#') {
a[i] = ch;
i++;
}
cin.get(ch);
ch = tolower(ch);
}
a[i] = '\0'; // <<<<<<<< Add this line
cout << "--> ";
cin.get(ch);
ch = tolower(ch);
i = 0;
while (ch != '\n')
{
if (ch > '#') {
b[i] = ch;
i++;
}
cin.get(ch);
ch = tolower(ch);
}
b[i] = '\0'; // <<<<<<<< Add this line
..
Here is the result:
Enter two lines that might be anagrams:
--> aabb
--> abba
String A is aabb
String B is abba
The two strings ARE anagrams.