Count Number of Homogenous Substrings LeetCode solution in C++

1
class Solution {
2
 public:
3
  int countHomogenous(string s) {
4
    int mod = 1e9 + 7, size = s.size(), i = 0, j = 0, count = 0;
5
    while (j < size) {
6
      if (s[j] != s[j + 1]) {
7
        long n = j - i + 1;
8
        count = count + (n * (n + 1) / 2) % mod;
9
        i = j + 1;
10
      }
11
      j++;
12
    }
13
    return count;
14
  }
15
};