class Solution{
    public: 
        bool checkOnesSegment(string s){
            return s.find("01") == string::npos;
        }
};

//TC: o(n), SC:o(1)


//npos is a special cpp constant stands for "no position" which is essentially not found value, (size_t(-1)) returned by find() and such functions

/*
find()
- finds FIRST occurrence of substring

Example:
string s = "banana";
s.find("na") -> 2

--------------------------------

rfind()
- finds LAST occurrence of substring

Example:
string s = "banana";
s.rfind("na") -> 4

--------------------------------

find_first_of()
- finds first character that matches
  ANY char from a given set

Example:
string s = "hello";
s.find_first_of("aeiou") -> 1  // 'e'

--------------------------------

find_last_of()
- finds last character that matches
  ANY char from a given set

Example:
string s = "hello";
s.find_last_of("aeiou") -> 4  // 'o'

--------------------------------
*/