/* This file contains the fragments of code from the lectures
   on chars and strings, for you to play around with.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>

/* we use this in several places */
#define NUMLETS 26

/* here is the roman number function repeated from roman.c */

void PrintNum(int n) {
  while (n > 0) {
    if (n >= 100) {
      n = n - 100;  putchar('C');
    } else if (n >= 90) {
      n = n + 10;  putchar('X');
    } else if (n >= 50) {
      n = n - 50;  putchar('L');
    } else if (n >= 40) {
      n = n + 10;  putchar('X');
    } else if (n >= 10) {
      n = n - 10;  putchar('X');
    } else if (n >= 9) {
      n = n + 1;  putchar('I');
    } else if (n >= 5) {
      n = n - 5;  putchar('V');
    } else if (n >= 4) {
      n = n + 1;  putchar('I');
    } else {
      n = n - 1;  putchar('I');
    }
  }
}

/* This function Caesar-enciphers standard input to standard output */

/* how much to rotate the alphabet: A -> N, B -> O, and so on. */
const int OFFSET = 13;

void CaesarCipher (void) {
  int c, ord;   /* Why is c declared as int and not char? */

  while ((c = getchar()) != EOF) {
    c = toupper(c);
    if (isupper(c)) {
      ord = c - 'A';                   /* Integer in range [0,25] */
      ord = (ord + OFFSET) % NUMLETS;  /* permute by offset */
      c = ord + 'A';                   /* back to char */
    }
    putchar(c);
  }
}

/* This function counts the frequencies of letters in the 
   standard input, and prints the results to standard output.
*/
void CountLetters(void) {
  int c,  i, count[NUMLETS];

  for (i = 0; i < NUMLETS; i++) count[i] = 0;
  while ((c = getchar()) != EOF) {
    c = toupper(c);
    if (isupper(c)) {
      i = c - 'A';              /* Integer in [0,25] */
      count[i]++;
    }
  }
  for (i = 0; i < NUMLETS; i++) {
    printf("%c: %d\n", i + 'A', count[i]);
  }
}

/* This function gives a count of the length of each line
   on standard input, echoing the line followed by the count
   to standard output.
*/
void LineLengths(void) {
  int c, charCount = 0, lineCount = 0;

  while ((c = getchar()) != EOF) {
    if (c == '\n') {
      lineCount++;
      printf("  [Line %d has %d characters]\n", 
                            lineCount, charCount);
      charCount = 0;
    } else {
      charCount++; 
      putchar(c);
    }
  }
}

int main(void) {

  /* Write your own main routine to call those functions */

  return EXIT_SUCCESS;
}