caesar.h

#ifndef CAESAR_H
#define CAESAR_H

#include <string>

extern const char kStart;
extern const char kEnd;

// Encrypt a single character.
char Encrypt(char input_char, int key);

// Decrypt a single character.
char Decrypt(char input_char, int key);

// Calculates mean-squared-error for top 3 letters in English language.
double MeanSquaredError(double e_freq, double t_freq, double a_freq);

#endif