1876. Substrings of Size Three with Distinct Characters.cpp

// TC - O(N)
// SC - O(1)
class Solution {
public:
    int countGoodSubstrings(string s) {
        int n = s.size(), count = 0;
        if(n < 3) return 0;
        for(int i = 0; i < n-2; i++) {
            if(s[i]!=s[i+1] && s[i]!=s[i+2] && s[i+1]!=s[i+2]) count++;
        }
        return count;
    }
};