55

Author: chirag127

cd.c

@@ -1,44 +1,35 @@
-//  1. Construct a Shift Reduce Parser for a given language
 
-// Including Libraries
+
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-// Global Variables
 int z = 0, i = 0, j = 0, c = 0;
-
-// Modify array size to increase
-// length of string to be parsed
 char a[16], ac[20], stk[15], act[10];
-
-// This Function will check whether
-// the stack contain a production rule
-// which is to be Reduce.
-// Rules can be E->2E2 , E->3E3 , E->4
 void check()
 {
-    // Copying string to be printed as action
+
     strcpy(ac, "REDUCE TO E -> ");
 
-    // c=length of input string
+
     for (z = 0; z < c; z++)
     {
-        // checking for producing rule E->4
+
         if (stk[z] == '4')
         {
             printf("%s4", ac);
             stk[z] = 'E';
             stk[z + 1] = '\0';
 
-            // printing action
+
             printf("\n$%s\t%s$\t", stk, a);
         }
     }
 
     for (z = 0; z < c - 2; z++)
     {
-        // checking for another production
+
         if (stk[z] == '2' && stk[z + 1] == 'E' &&
             stk[z + 2] == '2')
         {
@@ -53,7 +44,7 @@ void check()
 
     for (z = 0; z < c - 2; z++)
     {
-        // checking for E->3E3
+
         if (stk[z] == '3' && stk[z + 1] == 'E' &&
             stk[z + 2] == '3')
         {
@@ -65,64 +56,61 @@ void check()
             i = i - 2;
         }
     }
-    return; // return to main
+    return;
 }
 
-// Driver Function
+
 int main()
 {
     printf("GRAMMAR is -\nE->2E2 \nE->3E3 \nE->4\n");
 
-    // a is input string
-    strcpy(a, "32423");
 
-    // strlen(a) will return the length of a to c
+    strcpy(a, "23");
+
+
     c = strlen(a);
 
-    // "SHIFT" is copied to act to be printed
+
     strcpy(act, "SHIFT");
 
-    // This will print Labels (column name)
+
     printf("\nstack \t input \t action");
 
-    // This will print the initial
-    // values of stack and input
+
+
     printf("\n$\t%s$\t", a);
 
-    // This will Run upto length of input string
+
     for (i = 0; j < c; i++, j++)
     {
-        // Printing action
+
         printf("%s", act);
 
-        // Pushing into stack
+
         stk[i] = a[j];
         stk[i + 1] = '\0';
 
-        // Moving the pointer
+
         a[j] = ' ';
 
-        // Printing action
+
         printf("\n$%s\t%s$\t", stk, a);
 
-        // Call check function ..which will
-        // check the stack whether its contain
-        // any production or not
+
+
+
         check();
     }
 
-    // Rechecking last time if contain
-    // any valid production then it will
-    // replace otherwise invalid
+
+
+
     check();
 
-    // if top of the stack is E(starting symbol)
-    // then it will accept the input
+
+
     if (stk[0] == 'E' && stk[1] == '\0')
         printf("Accept\n");
-    else // else reject
+    else
         printf("Reject\n");
 }
-// This code is contributed by Ritesh Aggarwal
-
-// https://www.geeksforgeeks.org/shift-reduce-parser-compiler/

cd/11. Construct a Shift Reduce Parser for a given language./program

@@ -6,13 +6,13 @@ struct node
     struct node *link;
 };
 
-void findclosure(int, int);
-void insert_trantbl(int, char, int);
-int findalpha(char);
-void findfinalstate(void);
-void unionclosure(int);
-void print_e_closure(int);
-static int set[20], nostate, noalpha, s, notransition, nofinal, start, finalstate[20], c, r, buffer[20];
+void fc(int, int);
+void it(int, char, int);
+int fa(char);
+void ffs(void);
+void uc(int);
+void pec(int);
+static int set[20], ns, na, s, nt, nf, start, fs[20], c, r, b[20];
 char alphabet[20];
 static int e_closure[20][20] = {0};
 struct node *transition[20][20] = {NULL};
@@ -22,72 +22,72 @@ void main()
 
     struct node *temp;
     printf("enter the number of alphabets?\n");
-    scanf("%d", &noalpha);
+    scanf("%d", &na);
     getchar();
     printf("NOTE:- [ use letter e as epsilon]\n");
 
     printf("NOTE:- [e must be last character ,if it is present]\n");
 
     printf("\nEnter alphabets?\n");
-    for (i = 0; i < noalpha; i++)
+    for (i = 0; i < na; i++)
     {
 
         alphabet[i] = getchar();
         getchar();
     }
     printf("Enter the number of states?\n");
-    scanf("%d", &nostate);
+    scanf("%d", &ns);
     printf("Enter the start state?\n");
     scanf("%d", &start);
     printf("Enter the number of final states?\n");
-    scanf("%d", &nofinal);
+    scanf("%d", &nf);
     printf("Enter the final states?\n");
-    for (i = 0; i < nofinal; i++)
-        scanf("%d", &finalstate[i]);
+    for (i = 0; i < nf; i++)
+        scanf("%d", &fs[i]);
     printf("Enter no of transition?\n");
-    scanf("%d", &notransition);
-    printf("NOTE:- [Transition is in the form--> qno   alphabet   qno]\n", notransition);
+    scanf("%d", &nt);
+    printf("NOTE:- [Transition is in the form--> qno   alphabet   qno]\n", nt);
     printf("NOTE:- [States number must be greater than zero]\n");
     printf("\nEnter transition?\n");
-    for (i = 0; i < notransition; i++)
+    for (i = 0; i < nt; i++)
     {
 
         scanf("%d %c%d", &r, &c, &s);
-        insert_trantbl(r, c, s);
+        it(r, c, s);
     }
 
     printf("\n");
 
-    for (i = 1; i <= nostate; i++)
+    for (i = 1; i <= ns; i++)
     {
         c = 0;
         for (j = 0; j < 20; j++)
 
         {
-            buffer[j] = 0;
+            b[j] = 0;
             e_closure[i][j] = 0;
         }
-        findclosure(i, i);
+        fc(i, i);
     }
     printf("Equivalent NFA without epsilon\n");
     printf("-----------------------------------\n");
     printf("start state:");
-    print_e_closure(start);
+    pec(start);
     printf("\nAlphabets:");
-    for (i = 0; i < noalpha; i++)
+    for (i = 0; i < na; i++)
         printf("%c ", alphabet[i]);
     printf("\n States :");
-    for (i = 1; i <= nostate; i++)
-        print_e_closure(i);
+    for (i = 1; i <= ns; i++)
+        pec(i);
 
     printf("\nTnransitions are...:\n");
 
-    for (i = 1; i <= nostate; i++)
+    for (i = 1; i <= ns; i++)
     {
 
-        for (j = 0; j < noalpha - 1; j++)
+        for (j = 0; j < na - 1; j++)
         {
-            for (m = 1; m <= nostate; m++)
+            for (m = 1; m <= ns; m++)
                 set[m] = 0;
             for (k = 0; e_closure[i][k] != 0; k++)
             {
@@ -97,15 +97,15 @@ void main()
                 while (temp != NULL)
                 {
 
-                    unionclosure(temp->st);
+                    uc(temp->st);
                     temp = temp->link;
                 }
             }
             printf("\n");
-            print_e_closure(i);
+            pec(i);
             printf("%c\t", alphabet[j]);
             printf("{");
-            for (n = 1; n <= nostate; n++)
+            for (n = 1; n <= ns; n++)
             {
                 if (set[n] != 0)
                     printf("q%d,", n);
@@ -114,33 +114,33 @@ void main()
         }
     }
     printf("\n Final states:");
-    findfinalstate();
+    ffs();
 }
 
-void findclosure(int x, int sta)
+void fc(int x, int sta)
 {
     struct node *temp;
     int i;
-    if (buffer[x])
+    if (b[x])
         return;
     e_closure[sta][c++] = x;
-    buffer[x] = 1;
-    if (alphabet[noalpha - 1] == 'e' && transition[x][noalpha - 1] != NULL)
+    b[x] = 1;
+    if (alphabet[na - 1] == 'e' && transition[x][na - 1] != NULL)
     {
-        temp = transition[x][noalpha - 1];
+        temp = transition[x][na - 1];
         while (temp != NULL)
         {
-            findclosure(temp->st, sta);
+            fc(temp->st, sta);
             temp = temp->link;
         }
     }
 }
 
-void insert_trantbl(int r, char c, int s)
+void it(int r, char c, int s)
 {
     int j;
     struct node *temp;
-    j = findalpha(c);
+    j = fa(c);
     if (j == 999)
     {
         printf("error\n");
@@ -152,17 +152,17 @@ void insert_trantbl(int r, char c, int s)
     transition[r][j] = temp;
 }
 
-int findalpha(char c)
+int fa(char c)
 {
     int i;
-    for (i = 0; i < noalpha; i++)
+    for (i = 0; i < na; i++)
         if (alphabet[i] == c)
             return i;
 
     return (999);
 }
 
-void unionclosure(int i)
+void uc(int i)
 {
     int j = 0, k;
     while (e_closure[i][j] != 0)
@@ -172,26 +172,26 @@ void unionclosure(int i)
         j++;
     }
 }
-void findfinalstate()
+void ffs()
 {
     int i, j, k, t;
-    for (i = 0; i < nofinal; i++)
+    for (i = 0; i < nf; i++)
     {
-        for (j = 1; j <= nostate; j++)
+        for (j = 1; j <= ns; j++)
         {
             for (k = 0; e_closure[j][k] != 0; k++)
             {
-                if (e_closure[j][k] == finalstate[i])
+                if (e_closure[j][k] == fs[i])
                 {
 
-                    print_e_closure(j);
+                    pec(j);
                 }
             }
         }
     }
 }
 
-void print_e_closure(int i)
+void pec(int i)
 {
     int j;
     printf("{");