state transitions 0 takes to q4 , 1 takes to q2
if ( s [ i ] == '0' ) q4 ( s , i + 1 ) ; else q2 ( s , i + 1 ) ; } static void q4 ( string s , int i ) { Console . Write ( " q4 - > " ) ; if ( i == s . Length ) { Console . WriteLine ( " YES " ) ; return ; }