Driver code
int main ( ) { string s = " geeksforgeeks " ; cout << " The ▁ input ▁ String ▁ is ▁ " << s << endl ; int length = longestUniqueSubsttr ( s ) ; cout << " The ▁ length ▁ of ▁ the ▁ longest ▁ non - repeating ▁ character ▁ " << " substring ▁ is ▁ " << length ; }