Question

Programing in C

Create a text file with 1000 random H's and T's, then write a program to count how many times each of the pairs HH, HT, TH, TT occur. Each should occur equally often. (use getchar(), read until EOF.) Regard the file as a sequence of pairs (so pairs do not overlap.) If there are an odd number of characters, ignore the last one.

Example output:

HH occured 113 times

HT occured 128 times

TH occured 133 times

TT occured 126 times

Answer 1

#include
#include

int main(void)
{
   // initialise variables
FILE *fp;
int c1,c2;
int hhCount=0,ttCount=0,htCount=0,thCount=0;
fp = fopen("texgt.txt", "r");
if(fp==NULL)
   {
   // if error in opening a file
printf("Error in opening the file..!!");
   exit(1);
   }   
  

while((c1 = fgetc(fp)) != EOF)
{
   // read second character
   c2=fgetc(fp);
   if(c2==EOF)
   break;
  
if(c1=='H')
   {
   if(c2=='H') // this is HH
   hhCount++;
else // This is HT
   htCount++;
   }
   else
   {
   if(c2=='H') // this is TH
   thCount++;
else // this is TT
   ttCount++;
   }
  
}
// print output
printf("HH occured %d times\n",hhCount);
printf("HT occured %d times\n",htCount);
printf("TH occured %d times\n",thCount);
printf("TT occured %d times\n",ttCount);

fclose(fp);

return 0;
}

==================

SCREENSHOT:

OUTPUT:

RANDOM FILE:

HHTTTTHTHTTHHTTHTHHTHTTHTTTHTHTTTTTTTHHTTTHTTTHHHTHTHTTHHTHTTTTTTTTTTTTTHTHHTHHTHTTHTHHTTTHTHHHTHHHHTHTTHHTHTHTHHHHTHHTHTTTHTHTHHTHHHHHHTHHHTTHTHTTHHHHHHHHHHTHTTHHTHTHHHTTHTTHHTHHTHHTTHTTTTTTHTHTHTHHHHTHTHHHHHTHHTTTHTHTTTTTHTHTHHHHTHHTTHHHTHTHTHTTTHHHHTHHTTTHHTTTHTHTHTHTHTHHHHHHHTTHTHTHHHTTTHTHHHHTHHTHTTTHHTHTHHTTTTTHTHTTTHHHTTTTHHHHTTHTTTHHHTHTTHTTHTHHTTTHHTHHTHTTTTTHTHTTHTHTTHTTHTTTHTHHHHTHHTHTHTHHHTTTTTTHHTTHHHTTTHTHHHTHTTTHTHHTTHHHTTTHTHHTHHTTHTHHHHHTHHTHTTTHHHHTHTHTTHTTHHTHTTTTHHHTHHTTTTHHHHTHHTHTTHHTHHTHTTTTHHHTTHHHTHTTHHTTHTTTTTHTTHHTTHHTTTTTTTHHTTTHHTHHTHTHTHTTTTHHHTTHHHHHHTTTHHHHHTTHTHHHHHTHTTHHHTTTTTHTHHTHTHTHHHHTTTTHTTHHHTTTHHTTTHHHHHHHTTHHTHHTHHHTHHHTTHTHTTTHHHHTTTHTHTTTTTHTHTTHTTTTTHHTHHTTTTHHTHTHTHHHTTHHTTHTTHTTTHTHHHHTHTHTHHHHHHTHHTTHHTTHTTHTTTHHTHHHTHTTHTHHTHHHHHHTHTHHTTTTTHTTHTTHTHHTHHHHHTTHHTTHTHTHTHHHHTHTTTHTTTHTTTTTHTTTTHTHHHHHTTHHTTHTTHHTTTTTTHTHHTTTTTTHHTTTHTHTTHTTHTTTHTTTTHTHHHTTHTHHHTTTHHTHHHHHHHHHTHTHTHHHTTHHHHHHTHTTTTTTHHTTTTHHTHTTTTHTTHHTTTTHTTTHTHTTTHTTHHTHT

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