text: #include <stdlib.h>
  
  typedef struct
  {
  	char letter;
  	int quantity;
  
  } Letter;
  
  void initLetterArr( Letter *letterArr, const size_t letterArrLength );
  
  int readFile( const char *fileName, char *fileOutput );
  
  void calcLetterFrequency( const char *inputText, const int inputLength, Letter *letterArr );
  
  void printLetterFrequency( const Letter *letterArr, const size_t letterArrLength );
  
  