Create 1b.c

fatalcoder524 · web-flow · commit 281f764f30f6 · 2019-05-29T03:47:47.000+05:30
diff --git a/1b.c b/1b.c
@@ -0,0 +1,42 @@
+%{
+#include "y.tab.h"
+extern yylval;
+%}
+%%
+[0-9]+ {yylval=atoi(yytext);return num;} 
+[\+\-\*\/] {return yytext[0];}
+[)] {return yytext[0];}
+[(] {return yytext[0];}
+. {;}
+\n {return 0;}
+%%
+------------YACC Part----------
+%{
+#include<stdio.h>
+#include<stdlib.h>
+%}
+%token num
+%left '+' '-'
+%left '*' '/'
+%%
+input:exp {printf("%d\n",$$);exit(0);}
+exp:exp'+'exp {$$=$1+$3;}
+|exp'-'exp{$$=$1-$3;}
+|exp'*'exp{$$=$1*$3;}
+|exp'/'exp { if($3==0){printf("Divide by Zero\n");exit(0);}
+ else
+ $$=$1/$3;}
+|'('exp')'{$$=$2;}
+|num{$$=$1;};
+%%
+int yyerror()
+{
+printf("error");
+exit(0);
+} 
+
+int main()
+{
+printf("Enter an expression:\n");
+yyparse();
+}
