Code

Author: shah-deep

CYK.c

@@ -0,0 +1,186 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+
+bool checkNTR(char ch){
+    char big[] = {'S','A','B','C','D','E','F','G','H'};
+    for(int i=0; i<strlen(big); i++){
+        if(ch==big[i])
+            return true;
+    }
+    return false;
+}
+
+bool checkTR(char ch){
+    char small[] = {'a','b','c','d','e'};
+    for(int i=0; i<strlen(small); i++){
+        if(ch==small[i])
+            return true;
+    }
+    return false;
+}
+
+bool checkPR(char ch[]){
+        if(strlen(ch)==1){
+            if(checkTR(ch[0])){
+                return true;
+            }
+        } else if(strlen(ch)==2){
+            if(checkNTR(ch[0]) && checkNTR(ch[1])){
+               return true;
+            }
+        }
+    return false;
+}
+
+bool checkEle(char El[], char ch){
+    for(int i=0; i<strlen(El); i++){
+        if(ch==El[i]){
+            return true;
+        }
+    }
+    return false;
+}
+
+int main(){
+
+    printf("DEMO Input for Production : S->AB, S->e, A->a, B->b :\n\n");
+    printf("No. of production rules = 4\n\nEnter generating symbols:\n\nSymbol  Count\nS 2\nA 1\nB 1\n\nEnter Production rules :\n\nNon- Terminal   -->   Production\nS --> AB\nS --> e\nA --> a\nB --> b\n\n\n");
+
+
+    int n_pr=0, n_pr2=0, pr_cnt=0;
+
+    printf("Allowed Symbols: 'S','A','B','C','D','E','F','G','H' \n");
+    printf("Allowed terminals: 'a','b','c','d' and 'e':epsilon/lambda\n");
+    printf("\n\nNo. of production rules = ");
+    scanf("%d",&n_pr);
+    char ntr[n_pr], pr[n_pr][3];
+    int ntr_cnt[n_pr];
+
+    printf("\nEnter generating symbols:\n\nSymbol  Count\n");
+    fflush(stdin);
+    int i1=0;
+    while(n_pr2<n_pr){
+        scanf("%c %d",&ntr[i1],&ntr_cnt[i1]);
+        fflush(stdin);
+
+        if(!checkNTR(ntr[i1])){
+          printf("Invalid Input. Please choose from 'Allowed Symbols' and try again.\n\nExiting...\n");
+          return -1;
+        }
+        n_pr2 += ntr_cnt[i1];
+        i1++;
+    }
+
+    if(n_pr != n_pr2){
+        printf("Invalid Input for 'No. of production rules'. Please try again.\n\nExiting...\n");
+        return -1;
+    }
+
+    printf("\n\nEnter Production rules : \n");
+    printf("\nNon- Terminal   -->   Production\n");
+    fflush(stdin);
+    for(int i=0; i<i1; i++){
+        for(int j=0; j<ntr_cnt[i]; j++) {
+            printf("%c --> ",ntr[i]);
+            pr_cnt += (i+j);
+            fflush(stdin);
+            pr[pr_cnt][1]=pr[pr_cnt][2]='\0';
+            gets(pr[pr_cnt]);
+            fflush(stdin);
+            if(!checkPR(pr[pr_cnt])){
+               printf("Invalid Input. Please write correct CNF and try again.\n\nExiting...\n");
+               return -1;
+            }
+        }
+    }
+
+     pr_cnt = 0;
+     for(int i=0; i<i1; i++){
+        for(int j=0; j<ntr_cnt[i]; j++) {
+            pr_cnt += (i+j);
+            printf("\n%c --> %s",ntr[i],pr[pr_cnt]);
+        }
+    }
+
+    fflush(stdin);
+    int n=0;
+    printf("\n\nInput String: ");
+    char s1[10];
+    gets(s1);
+    fflush(stdin);
+    n = strlen(s1);
+    char st[n];
+    strcpy(st,s1);
+    char tb[n][n][10]; // Table
+
+    if(n==0){
+        printf("Empty String!\n");
+        return -1;
+    }
+
+
+    for(int i=0; i<n; i++){
+        for(int j=0; j<n; j++){
+            for(int k=0; k<10; k++)
+                tb[i][j][k]='\0';
+        }
+    }
+
+    for(int i=0;i<n;i++){
+        pr_cnt = 0;
+        int  k2 = 0;
+         for(int i2=0; i2<i1; i2++){
+            for(int j2=0; j2<ntr_cnt[i2]; j2++) {
+                pr_cnt += (i2+j2);
+                if(checkTR(pr[pr_cnt][0]) && pr[pr_cnt][0]==st[i]){
+                    tb[i][i][k2]=ntr[i2];
+                    k2+=1;
+                }
+            }
+        }
+    }
+
+    for(int l=1; l<=(n-1); l++){
+        for(int i=0, j=0; i<=(n-l-1); i++){
+            j = i+l;
+
+          for(int k=i; k<=(j-1); k++){
+              pr_cnt = 0;
+              int k2 = 0;
+
+              for(int i2=0; i2<i1; i2++){
+                 for(int j2=0; j2<ntr_cnt[i2]; j2++) {
+
+                    pr_cnt += (i2+j2);
+                    if(checkNTR(pr[pr_cnt][0])){
+                        if(checkEle(tb[i][k],pr[pr_cnt][0]) && checkEle(tb[k+1][j],pr[pr_cnt][1])){
+                            tb[i][j][k2]=ntr[i2];
+                            k2+=1;
+                        }
+                    }
+                }
+             }
+           }
+        }
+    }
+
+
+printf("\n\n\nTable:\n\n");
+
+    for(int i=0; i<n; i++){
+            printf("|");
+        for(int j=0; j<n; j++){
+            printf("%s |",tb[i][j]);
+        }
+        printf("\n");
+    }
+
+    if(checkEle(tb[0][n-1],'S')){
+        printf("\n\nThis String is Accepted!\n\n");
+    } else{
+        printf("\n\nThis String is Rejected!\n\n");
+    }
+
+    return 0;
+}