Package g1701_1800.s1759_count_number_of_homogenous_substrings

Class Solution

java.lang.Object
g1701_1800.s1759_count_number_of_homogenous_substrings.Solution
public class Solution extends java.lang.Object
1759 - Count Number of Homogenous Substrings.

Medium

Given a string s, return the number of homogenous substrings of s. Since the answer may be too large, return it modulo 109 + 7.

A string is homogenous if all the characters of the string are the same.

A substring is a contiguous sequence of characters within a string.

Example 1:

Input: s = “abbcccaa”

Output: 13

Explanation: The homogenous substrings are listed as below:

“a” appears 3 times.

“aa” appears 1 time.

“b” appears 2 times.

“bb” appears 1 time.

“c” appears 3 times.

“cc” appears 2 times.

“ccc” appears 1 time.

3 + 1 + 2 + 1 + 3 + 2 + 1 = 13.

Example 2:

Input: s = “xy”

Output: 2

Explanation: The homogenous substrings are “x” and “y”.

Example 3:

Input: s = “zzzzz”

Output: 15

Constraints:

  • 1 <= s.length <= 105
  • s consists of lowercase letters.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    countHomogenous(java.lang.String s)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • countHomogenous

      public int countHomogenous(java.lang.String s)