Question

Write a C program to do the following:

• Read the contents of 3 files (BE340_Exam_A.txt, BE340_Exam_B.txt, BE340_Exam_C.txt)
• Read each character from BE340_Exam_A, BE340_Exam_B, and BE340_Exam_C, and add them together to obtain each decrypted character
• Write each decrypted character to an output file and also output each character to the screen

Answer 1

1 #include<stdio.h> 2 #include<string.h> #include<ctype.h> . 5 int main() 6 FILE fp1,*fp2 , *fp3 , *fp4; //opening files in read mode fp1-fopen"BE340_Exam_A. txt","r"); fp2=fopen("BE340_Exam_B . txt","r"); fp3=fopen("BE340_Exam_C. txt" , "r"); 7 11 //opening output file in append mode fp4 fopen"output. txt","a"); //declaring char variables char ch1,ch2,ch3; char ch[3]; 12 13 14 15 17 //getting characters from pointer ch1 fgetc(fp1); ch2-fgetc(fp2); ch3=fgetc(fp3); while (ch1!= EOF ) / /if it is not end of the file 18 19 20 21 22 if (isal isalpha(ch2) && isalpha(ch3 ) ) { //if the characters are alphabets ch[0] ch1; ch[1]-ch2; ch[2] ch3; printf("%s",ch); //printing characters fprintf(fp4, "%s", ch); //appending characters to output file 24 25 26 27 28 ch1-fgetc(fp1); ch2-fgetc (fp2 ); ch3-fgetc(fp3); 30 31 32 } printf("\n"); 33 34 return 35 36

#include<stdio.h>
#include<string.h>
#include<ctype.h>

int main(){
   FILE *fp1,*fp2,*fp3,*fp4;   
   //opening files in read mode
   fp1=fopen("BE340_Exam_A.txt","r");
   fp2=fopen("BE340_Exam_B.txt","r");
   fp3=fopen("BE340_Exam_C.txt","r");
  
   //opening output file in append mode
   fp4=fopen("output.txt","a");
   //declaring char variables
   char ch1,ch2,ch3;
   char ch[3];
  
   //getting characters from pointer
   ch1=fgetc(fp1);
   ch2=fgetc(fp2);
   ch3=fgetc(fp3);
   while (ch1!=EOF){ //if it is not end of the file
       if (isalpha(ch1) && isalpha(ch2) && isalpha(ch3)){ //if the characters are alphabets
           ch[0]=ch1;
           ch[1]=ch2;
           ch[2]=ch3;
           printf("%s",ch); //printing characters
           fprintf(fp4, "%s", ch); //appending characters to output file
       }
       ch1=fgetc(fp1);
       ch2=fgetc(fp2);
       ch3=fgetc(fp3);
   }
   printf("\n");
   return 0;
}

jack@jack-TravelMate-P243-M:~$ ./a.out AIQBJRCKSDLTEMUFNVGOWHPX jack@jack-TravelMate-P243 -M:~$ ]

I think this is the correct answer.

If you want any change comment me.