state transitions 0 takes to q1 , 1 takes to q3
if ( s [ i ] == '0' ) q1 ( s , i + 1 ) ; else q3 ( s , i + 1 ) ; } static void q2 ( string s , int i ) { Console . Write ( " q2 - > " ) ; if ( i == s . Length ) { Console . WriteLine ( " NO ▁ " ) ; return ; }