ans to 0 to store the final count of homogenous substrings.currStreak to 0 to keep track of the current streak of identical characters.MOD as 10^9 + 7 for modulo operations.i of the string s:
a. If i == 0 or s[i] == s[i - 1], increment currStreak.
b. Otherwise, reset currStreak to 1.
c. Add currStreak to ans modulo MOD.ans.