leetcode

0 class Solution {

1 public:

2 int numberOfSubstrings(const string &s) {

3 int st[3] = {0}, count = 0, res = 0, left = 0;

4 for (int i = 0; i < s.size(); i++) {

5 if (!st[s[i] - 'a']++) count++;

6 while (count == 3) {

7 res += s.size() - i;

8 if (!--st[s[left++] - 'a']) count--;

9 }

10 }

11 return res;

12 }

13 };