Added grammer fixes for nesting counts

Author: KTS-o7

Lab New Codes/nestedIf/lex.l

@@ -1,10 +1,15 @@
 %{
-    #include "y.tab.h"
+#include "y.tab.h"
 %}
+
 %%
-"if"    {return IF;}
-[a-zA-Z]*   {return IDEN;}
-[0-9]+  {return NUM;}
-[\n ]   ;
-.   {return yytext[0];}
-%%
+"if"        { return IF; }
+[a-zA-Z][a-zA-Z0-9]* { return IDEN; }
+[0-9]+      { return NUM; }
+[ \t\n]+    ; 
+.           { return yytext[0]; }
+%%
+
+int yywrap() {
+    return 1;
+}

Lab New Codes/nestedIf/yacc.y

@@ -1,41 +1,68 @@
 %{
-    #include<stdio.h>
-    #include<stdlib.h>
-    int cnt=0;
+    #include <stdio.h>
+    #include <stdlib.h>
+    int total_if_count = 0;
+    int current_nesting = 0;
+    int max_nesting = 0;
+    int yylex();
+    int yyerror(const char *s);
 %}
+
 %token IF IDEN NUM
+
 %%
-S:I
-;
-I:IF A B    {cnt++;}
-;
-A:'('E')'
-;
-E:IDEN Z IDEN
-|IDEN Z NUM
-|IDEN U
-|IDEN
-;
-Z:'='|'<'|'>'|'<''='|'>''='|'=''+'|'=''-'
-;
-U:'+''+'|'-''-'
-;
-B:B B
-|'{'B'}'
-|I
-|E';'
-|
-;
+
+STMTS: STMT
+     | STMTS STMT
+     ;
+
+STMT: IFSTMT
+    | IDEN '=' EXPR ';'
+    | IDEN ';'
+    | '{' STMTS '}'
+    | ';'
+    ;
+
+IFSTMT: IF '(' COND ')' 
+            {
+                total_if_count++;
+                current_nesting++;
+                if (current_nesting > max_nesting) {
+                    max_nesting = current_nesting;
+                }
+            }
+            STMT
+            {
+                current_nesting--;
+            }
+            ;
+
+COND: IDEN CMP IDEN
+         | IDEN CMP NUM
+         | IDEN
+         | NUM
+         ;
+
+CMP: '=' | '<' | '>' | '<''=' | '>''=' | '!''='
+          ;
+
+EXPR: IDEN
+          | NUM
+          | IDEN '+' IDEN
+          | IDEN '-' IDEN
+          ;
+
 %%
-int main()
-{
-    printf("Enter the snippet:\n");
+
+int main() {
+    printf("Enter the code snippet (Ctrl+D to end input on Unix, Ctrl+Z on Windows):\n");
     yyparse();
-    printf("Count of if is %d\n",cnt);
+    printf("\nTotal IF STMTS: %d\n", total_if_count);
+    printf("Maximum nesting level: %d\n", max_nesting);
     return 0;
 }
-int yyerror()
-{
-    printf("Invalid\n");
-    exit(0);
+
+int yyerror(const char *s) {
+    fprintf(stderr, "Parse error: %s\n", s);
+    exit(1);
 }

Prog3/a/lex.l

@@ -3,7 +3,6 @@
 %}
 %%
 "for" return FOR;
-"int"|"float"|"double"|"bool" return TYPE;
 ">"|"<"|">="|"<="|"=="|"!=" return OP;
 [a-zA-Z]* return IDEN;
 [0-9]+ return NUM;

Prog3/a/yacc.y

@@ -1,64 +1,81 @@
 %{
-	#include<stdio.h>
-	#include<stdlib.h>
-	int yylex();
-	int yyerror();
-	int cnt=0;
+    #include <stdio.h>
+    #include <stdlib.h>
+    int total_for_count = 0;      // Total count of for loops
+    int current_nesting = 0;      // Current level of nesting
+    int max_nesting = 0;          // Maximum level of nesting encountered
+    int yylex();
+    int yyerror(const char *s);
 %}
-%token FOR IDEN NUM TYPE OP
-%left '+' '-'
-%left '*' '/'
+
+%token FOR IDEN NUM OP
+
 %%
 
-// Tokens
+// List of statements
+STMTS: STMT
+     | STMTS STMT
+     ;
 
-// FOR -> for
-// IDEN -> identifier
-// NUM -> number
-// TYPE -> datatype
-// OP -> relational operator
+// Possible statements
+STMT: FORSTMT                // For loop
+    | IDEN '=' EXPR ';'      // Assignment
+    | IDEN ';'               // Identifier followed by semicolon
+    | '{' STMTS '}'          // Block of statements
+    | ';'                    // Empty statement
+    ;
 
-// Non-terminals
+// For loop structure
+FORSTMT: FOR '(' ASSGN ';' COND ';' ASSGN ')' 
+            {
+                total_for_count++;              // Increment for loop count
+                current_nesting++;              // Increase nesting level
+                if (current_nesting > max_nesting) {
+                    max_nesting = current_nesting;  // Track maximum nesting level
+                }
+            }
+            STMT
+            {
+                current_nesting--;              // Decrease nesting level after loop ends
+            }
+            ;
 
-// S -> Start symbol
-// BODY -> Body  of For loop
-// COND -> Condition
-// S1 -> Single Statement
-// SS -> Set of statements
-// T -> Term
-// E -> Expression
-// F -> For loop block
-// DA -> Declaration or assignment
-// DECL -> Declaration
-// ASSGN -> Assignment
+// Assignment inside for loop (initialization or update)
+ASSGN: IDEN '=' EXPR
+    | IDEN 
+    |
+      ;
 
-S:F;
-F:FOR'('DA';'COND';'S1')'BODY { cnt++; } |
-  FOR'(' ';'COND';'S1')'BODY { cnt++; } |
-  FOR'('DA';' ';'S1')'BODY { cnt++; } |
-  FOR'(' ';' ';'S1')'BODY { cnt++; } ;
+// Condition inside for loop
+COND: IDEN OP IDEN
+     | IDEN OP NUM
+     | IDEN
+     | NUM
+     ;
 
-DA:DECL|ASSGN
-DECL: TYPE IDEN | TYPE ASSGN;
-ASSGN : IDEN '=' E;
-COND : T OP T;
-T : NUM | IDEN ;
 
-BODY: S1';' | '{'SS'}' | F |';';
+// Expressions (simple arithmetic or identifier/number)
+EXPR: IDEN
+     | NUM
+     | IDEN '+' IDEN
+     | IDEN '-' IDEN
+     | IDEN '*' IDEN
+     | IDEN '/' IDEN
+     ;
 
-SS: S1 ';' SS | F SS |;
-S1: ASSGN | E | DECL ;
-E : E '+' E | E '-' E | E '*' E | E '/' E | '-''-'E | '+''+'E | E'+''+' | E'-''-' | T ;
 %%
-int main()
-{
-	printf("Enter the snippet:\n");
-	yyparse();
-	printf("Count of for : %d\n",cnt);
-	return 0;
+
+// Main function to handle user input and parse
+int main() {
+    printf("Enter the code snippet (Ctrl+D to end input on Unix, Ctrl+Z on Windows):\n");
+    yyparse();
+    printf("\nTotal FOR loops: %d\n", total_for_count);
+    printf("Maximum nesting level: %d\n", max_nesting);
+    return 0;
 }
-int yyerror()
-{
-	printf("Invalid\n");
-	exit(0);
+
+// Error handling
+int yyerror(const char *s) {
+    fprintf(stderr, "Parse error: %s\n", s);
+    exit(1);
 }

README.md

@@ -75,8 +75,8 @@ Input format for each of the programs
 
 3.  > a. Count the number of valid nested FOR loops
     ```bash
-    for(a;b;c){}
-    for(a;b;c){for(a;b;c){d;}}
+    for(a;b<c;c);
+    for(i=0;i<10;i){for(j=0;j<10;j);}
     ```
     > b. Validate function defination
     ```bash