Click here to download dateconv.c.

/***************************************************
Date conversion program

Write a program that reads in a date in the form

  <month name> <day>, <year>

(for example, "January 12, 2017"), and prints out
the same date in the form

  <month>/<day/<last year digits>

(for example, "01/12/17").
***************************************************/
#include "si204.h"

int main() {
  // Read date
  cstring mname;
  int day;
  int year;
  readstring(mname, stdin);
  day = readnum(stdin);
  readchar(stdin); // the comma
  year = readnum(stdin);

  int month = 0;
  // compute year number
  int shortyear = year % 100;

  // compute month number
  if (strcmp(mname, "January") == 0) {
    month = 1;
  } else if (strcmp(mname, "February") == 0) {
    month = 2;
  } else if (strcmp(mname, "March") == 0) {
    month = 3;
  } else if (strcmp(mname, "April") == 0) {
    month = 4;
  } else if (strcmp(mname, "May") == 0) {
    month = 5;
  } else if (strcmp(mname, "June") == 0) {
    month = 6;
  } else if (strcmp(mname, "July") == 0) {
    month = 7;
  } else if (strcmp(mname, "August") == 0) {
    month = 8;
  } else if (strcmp(mname, "September") == 0) {
    month = 9;
  } else if (strcmp(mname, "October") == 0) {
    month = 10;
  } else if (strcmp(mname, "November") == 0) {
    month = 11;
  } else if (strcmp(mname, "December") == 0) {
    month = 12;
  }

  // print month
  if (month < 10) {
    fputs("0", stdout);
  }
  writenum(month, stdout);

  fputs("/", stdout);

  // print day
  if (day < 10) {
    fputs("0", stdout);
  }
  writenum(day, stdout);

  fputs("/", stdout);

  // print year
  if (shortyear < 10) {
    fputs("0", stdout);
  }
  writenum(shortyear, stdout);

  fputs("\n", stdout);

  return 0;
}