YACC program which accept strings that starts and ends with 0 or 1
Problem: Write a YACC program which accept strings that starts and ends with Zero or One
Explanation:
YACC (Yet another Compiler-Compiler) is the standard parser generator for the Unix operating system. An open source program, yacc generates code for the parser in the C programming language. The acronym is usually rendered in lowercase but is occasionally seen as YACC or Yacc.
Examples:
Input: 001100 Output: Sequence Accepted Input: 1001001 Output: Sequence Accepted Input: 0011101 Output: Sequence Rejected Input: 100110 Output: Sequence Rejected
Lexical Analyzer Source Code :
%{ /* Definition section */ extern int yylval;%} /* Rule Section */%% 0 {yylval = 0; return ZERO;} 1 {yylval = 1; return ONE;} .|\n {yylval = 2; return 0;} %% |
Parser Source Code :
%{ /* Definition section */ #include<stdio.h> #include <stdlib.h> void yyerror(const char *str) { printf("\nSequence Rejected\n"); } %} %token ZERO ONE /* Rule Section */%% r : s {printf("\nSequence Accepted\n\n");}; s : n| ZERO a| ONE b; a : n a| ZERO; b : n b| ONE; n : ZERO| ONE; %% #include"lex.yy.c"//driver codeint main() { printf("\nEnter Sequence of Zeros and Ones : "); yyparse(); printf("\n"); return 0; } |
Output:
Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.
