Number of Equal Count Substrings in Java

An integer count is given to us associated with a string 'str' made up of lowercase English letters. The objective behind this particular problem is to find "equal count substrings." When every distinct letter appears within a substring exactly count times, the substring is said to be equal count. In essence, the task is to identify any substring in which the count is equal to the frequency of each unique letter within the substring. Next, we must provide the total number of these substrings back.

Example 1:

Input:

String str = "aaa"

int count = 3

Output:

The number of equal counts of sub strings is 1

Explanation:

In the given string, the substring "aaa" is the string that begins at index 0 and ends at index 2. "aaa" is the substring that goes from index 0 to index 2. There is specifically one instance of the letter "a" in the substring.

Example 2:

Input:

String str = "xxxyzyyzz"

int count = 3

Output:

The number of equal counts of sub strings is 3

Explanation:

In the given string, the substring "xxx" is the string that begins at index 0 and ends at index 2. In the substring, the letter "x" appears exactly three times. "yzyyzz" is the substring that exists between index 3 and index 8. There are exactly three instances of the letters "y" and "z" in the substring. "xxxyzyyzz" is the substring that goes from index 0 to index 8. There are specifically three instances of the letters "x," "y," and "z" in the substring.

Example 3:

Input:

String str = "pqrs"

int count = 3

Output:

The number of equal counts of sub strings is 0

Explanation:

In the given string, each letter appears less frequently than count times in the String 'str'. Consequently, return 0 because none of the substrings in s are equal count substrings.

Approach:

Implementation:

FileName: NumberEqualSubstrings.java

Output

The number of equal counts of sub strings is : 1

Complexity Analysis:

The above code's time complexity is O(N), and its space complexity is O(1).