Otherwise
return 0 ; } static int count ( StringBuilder a , char c ) { int count = 0 ; for ( int i = 0 ; i < a . Length ; i ++ ) if ( a [ i ] == c ) count ++ ; return count ; } static void swap ( StringBuilder s1 , int index1 , StringBuilder s2 , int index2 ) { char c = s1 [ index1 ] ; s1 [ index1 ] = s2 [ index2 ] ; s2 [ index2 ] = c ; }