Programming in C

The following code was written for various homework and lab assignments for a computer science course (CS159) taken during my first semester of freshman year (2017).

Homework 5 source code

/***************************************************************************
*
*  Programmer and Purdue Email Address:
*  1. liu2102@purdue.edu
*
*  Homework #: 5
*
*  Academic Integrity Statement:
*
*       I have not used source code obtained from
*       any other unauthorized source, either modified
*       or unmodified.  Neither have I provided access
*       to my code to another. The project I am submitting
*       is my own original work.
*
*  Lab Division and Section: 9:30-11:20 AM Friday 
*
*  Program Description: This program will create an encrypted key given an octal number and an octal digit to create the new key. 
*
***************************************************************************/
#include <stdio.h>
#include <math.h>

//Function Declarations
  void getInput(int*, int*);
  int calcSize(int);
  int calcEncrypted(int, int, int);
  void printResults(int, int);
int main()
{
//Local Declarations
  int number; //the given octal number from the user
  int key; //the given octal digit that serves as the key from the user
  int numberSize; //the size of the octal number from the user
  int encrypted; //the new calculated encrypted value
  
//Executable Statements
  getInput(&number, &key);
  numberSize = calcSize(number);
  encrypted = calcEncrypted(number, key, numberSize);
  printResults(numberSize, encrypted);
  
  return 0;
}

/***************************************************************************
*
*     Function Information
*
*     Name of Function: getInput
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int*, number, the given octal number from the user
*       2. int*, key, the given octal digit that serves as the key from the user
*       3.
*
*     Function Description: This function will ask the user to input the octal number and the octal digit. 
***************************************************************************/
void getInput(int* number, int* key)
{
//Local Declarations
  int isolatedNum; //the isolated digit from the number to use for testing
  int localNum; //set the given number to a local variable to use for testing only
  
//Executable Statements
  printf("Enter octal number: ");
  scanf("%d", number);
  
  do
  {
    localNum = *number;

    while(localNum > 0)
    {
      isolatedNum = localNum % 10;
       
      
      if (isolatedNum > 7)
      {
        printf("\nError! Input contains invalid digit!!\n");
            printf("\nEnter octal number: ");
        scanf("%d", number);
            localNum = *number;
      }
      
      localNum = localNum / 10;
      
      if (*number < 0)
      {
        printf("\nError! Negative numbers are invalid!!\n");
          printf("\nEnter octal number: ");
        scanf("%d", number);
      }
    } 
  } while(localNum > 0);

   printf("Enter octal key digit: ");
   scanf("%d", key); 
  do
  {  
    
    if (*key > 7)
    {
      printf("\nError! Invalid octal digit value!!\n");
      printf("\nEnter octal key digit: ");
      scanf("%d", key);
    }
  
    if (*key < 0)
    {
      printf("\nError! Invalid octal digit value!!\n");
        printf("\nEnter octal key digit: ");
      scanf("%d", key);
    }
  } while(*key > 7 || *key < 0);
  return;
} //getInput

/***************************************************************************
*
*     Function Information
*
*     Name of Function: calcSize
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: int
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, number, the given number from the user
*       2.
*       3.
*
*     Function Description: This function will calculate the size of the given number to use later.
***************************************************************************/
int calcSize(int number)
{
//Local Declarations
  int numberSize; //the size of the given number

//Executable Statements
  numberSize = 0;
  while(number > 0)
  {
    number = number / 10;
    numberSize = numberSize + 1;
  }
  
  return(numberSize);
} //calcSize

/***************************************************************************
*
*     Function Information
*
*     Name of Function: calcEncrypted
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: int
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, number, the given number from the user
*       2. int, key, the given key digit from the user
*       3. int, numberSize, the size of the given number from the user
*
*     Function Description: This function will calculate the new encrypted value. 
***************************************************************************/
int calcEncrypted(int number, int key, int numberSize)
{
//Local Declarations
  int isolatedNum; //the isolated digit from the number to use for testing
  int newDigit; //the digit of the encrypted value
  int count; //the count as the loop control update
  int encValue; //the total value of the encrypted value
  int decrement; //the decrement to use when calculating the encrypted value
  
//Executable Statements
  encValue = 0;
  count = 0;
  decrement = 1;
  do
  {
  isolatedNum = number / pow(10, numberSize - decrement);
  count++;
  newDigit = isolatedNum + key;
    if(newDigit > 7)
    {
      newDigit = newDigit % 8;
    }
  key = newDigit;
  number = number - (pow(10, numberSize - decrement) * isolatedNum);
  decrement++;
  encValue = encValue * 10 + newDigit;
 
  } while(count < numberSize);
  
  
  return(encValue);
}
/***************************************************************************
*
*     Function Information
*
*     Name of Function: printResults
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, numberSize, the given number from the user
*       2. int, encrypted, the calculated encrypted value 
*       3.
*
*     Function Description: This function will calculate the size of the given number to use later.
***************************************************************************/
void printResults(numberSize, encrypted)
{
//Executable Statements
  printf("\n-----------------%.*s\n", numberSize, "--------------------");
  printf("Encrypted Value: %0*d\n", numberSize, encrypted);
    printf("-----------------%.*s\n", numberSize, "--------------------");

}

hw #5

This assignment asked a user to input an octal (base 8) number followed by an octal digit. The octal digit serves as the initial key to be applied to the left-most digit of the octal number. From these two inputs, an encrypted number was generated by changing each individual number. Input validation was included, and checked to ensure integers were between 0 and 8.

HW #5 Sample Executions

As seen in execution 4, input validation ensured that the integer values were in between 0 and 8.

Homework 4 source code

/***************************************************************************
*
*  Programmer and Purdue Email Address:
*  1. liu2102@purdue.edu
*
*  Homework #: 4
*
*  Academic Integrity Statement:
*
*       I have not used source code obtained from
*       any other unauthorized source, either modified
*       or unmodified.  Neither have I provided access
*       to my code to another. The project I am submitting
*       is my own original work.
*
*  Lab Division and Section: Friday 9:30 AM
*
*  Program Description: This program will calculate the date of October and Thanksgiving break given the year and the day of the year that the fall semester begins
*
***************************************************************************/
#include <stdio.h>

//Function Declarations
  void getInput(int*, int*, int*);
  void calcDate(int, int, int, int*, int*, int*);
  void calcFallBreak(int, int, int*, int*, int*);
  void calcThanksgiving(int, int, int*, int*);
  void printResults(int, int, int, int, int, int, int, int);
  void printDefault(int, int, int);

int main()
{
//Local Executions
  int year; //the year that is given by the user
  int days; //the number of days into the year that the semester starts on
  int leapYear; //holds either 1 or 0 after calculating whether a year is a leap year or not 
  int month; //the month that the inputed start date is in 
  int startMonth; //the month of the semester start day
  int dayOfMonth; //holds the calculated day of month that the inputed start date falls on
  int monday; //holds the day of the week, which should be 1
  int day1; //the first day of the month that october break starts
  int day2; //the second day of the month that october break starts
  int thanksStartDate; //the calculated value of the day that thanksgiving break will start on
  int thanksEndDate;  //the calculated value of the day that thanksgiving break will end on
  
//Executables
  getInput(&year, &days, &leapYear);
  calcDate(days, leapYear, year, &startMonth, &dayOfMonth, &monday);
  calcFallBreak(days, leapYear, &month, &day1, &day2);
  calcThanksgiving(year, leapYear, &thanksStartDate, &thanksEndDate);
  
  if (monday != 1) //Asks if the value of monday is 1, and if it isn't, it will print the default statement
  {
    printDefault(startMonth, dayOfMonth, year);
  }
  else
  {
    printResults(month, startMonth, dayOfMonth, year, day1, day2, thanksStartDate, thanksEndDate);
  }
  return 0;
}

/***************************************************************************
*
*     Function Information
*
*     Name of Function: getInput
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: double
*
*     Parameters (list data type, name, and comment one per line):
*       1. int*, year, the given year from the user
*       2. int*, day, the number of days into the year that the semester starts on
*       3. int*, leapYear, the true or false (1 or 0) value of if the inputed year is a leap year
*
*     Function Description: This function will ask the user for the year and the day number on which the fall semester begins and then calculates if the inputed year is a leap year
*
***************************************************************************/
void getInput(int* year, int* days, int* leapYear)
{
//Statements
  printf("Enter the year: ");
  scanf("%d", year);
  
  printf("Enter the day number on which the fall semester begins: ");
  scanf("%d", days);
  
   *leapYear = (!(*year % 4) && (*year % 100)) || !(*year % 400);
  return;

} //getInput

/***************************************************************************
*
*     Function Information
*
*     Name of Function: calcDate
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, days, the number of days into the year that the semester starts on
*       2. int*, startMonth, the calculated value of the month that the start date falls in
*       3. int*, dayOfMonth, the calculated day of the month that the day is
*           4. int, leapYear, the true or false (1 or 0) value of if the inputed year is a leap year
*           5. int, year, the inputed year
*           6. int*, monday, calculates whether or not the value is on monday
*
*     Function Description: This function will calculate the month and day of month that the given semester start days is
*
***************************************************************************/

void calcDate(int days, int leapYear, int year, int* startMonth, int* dayOfMonth, int* monday)
{
//Statements
  //Will calculate the date of the first day, and the day of the week it starts on (should = 1)
  if (days <= 31)
  {
    *startMonth = 1;
      *dayOfMonth = days;
      *monday = (0 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
  else if(days > 31 && days <= 59)
  {
    *startMonth = 2;
    *dayOfMonth = days - 31;
    *monday = (31 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  } 
  else if((days > 59 + leapYear) && (days <= 90 + leapYear))
  {
    *startMonth = 3;
      *dayOfMonth = days - 59 - leapYear;
      *monday = (59 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 90 + leapYear) && (days <= 120 + leapYear))
  {
    *startMonth = 4;
      *dayOfMonth = days - 90 - leapYear;
      *monday = (90 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 120 + leapYear) && (days <= 151 + leapYear))
  {
    *startMonth = 5;
      *dayOfMonth = days - 120 - leapYear;
      *monday = (120 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 151 + leapYear) && (days <= 181 + leapYear))
  {
    *startMonth = 6;
    *dayOfMonth = days - 151 - leapYear;
    *monday = (151 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 181 + leapYear) && (days <= 212 + leapYear))
  {
    *startMonth = 7;
    *dayOfMonth = days - 181 - leapYear;
    *monday = (181 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 212 + leapYear) && (days <= 243 + leapYear))
  {
    *startMonth = 8;
    *dayOfMonth = days - 212 - leapYear;
    *monday = (212 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 243 + leapYear) && (days <= 273 + leapYear))
  {
    *startMonth = 9;
    *dayOfMonth = days - 243 - leapYear;
    *monday = (243 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 273 + leapYear) && (days <= 304 + leapYear))
  {
    *startMonth = 10;
    *dayOfMonth = days - 273 - leapYear;
    *monday = (273 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
   else if((days > 304 + leapYear) && (days <= 334 + leapYear))
  {
    *startMonth = 11;
    *dayOfMonth = days - 304 - leapYear;
    *monday = (304 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
    else if((days > 334 + leapYear) && (days <= 365 + leapYear))
  {
    *startMonth = 12;
    *dayOfMonth = days - 334 - leapYear;
    *monday = (334 + (*dayOfMonth + year + (year / 4) - 2)) % 7;
  }
  
  return;
} //calcDate

/***************************************************************************
*
*     Function Information
*
*     Name of Function: calcFallBreak
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, days, the number of days into the year that the semester starts on
*       2. int*, month, the calculated value of the month that the start date falls in
*       3. int*, day1, the first day that october break will fall on
*           4. int*, day2, the second day that october break will fall on
*           5. int, leapYear, the true or false (1 or 0) value of if the inputed year is a leap year
*
*     Function Description: This function will calculate the date of october fall break using the semester start date.
*
***************************************************************************/
void calcFallBreak(int days, int leapYear, int* month, int* day1, int* day2)
{
//Local Declarations
  int dayOfMonth; 
  int weekDay;
  
//Statements 
  days = days + 56 + leapYear;
  
  //After adding 56 days, calculates whether the days are between a certain value (month)
   if (days <= 31)
  {
    *month = 1;
    dayOfMonth = days;
    weekDay = dayOfMonth % 7;
  }
  else if(days > 31 && days <= 59)
  {
    *month = 2;
    dayOfMonth = days - 31;
    weekDay = dayOfMonth % 7;
  } 
  else if((days > 59 + leapYear) && (days <= 90 + leapYear))
  {
    *month = 3;
    dayOfMonth = days - 59 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 90 + leapYear) && (days <= 120 + leapYear))
  {
    *month = 4;
    dayOfMonth = days - 90 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 120 + leapYear) && (days <= 151 + leapYear))
  {
    *month = 5;
    dayOfMonth = days - 120 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 151 + leapYear) && (days <= 181 + leapYear))
  {
    *month = 6;
    dayOfMonth = days - 151 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 181 + leapYear) && (days <= 212 + leapYear))
  {
    *month = 7;
    dayOfMonth = days - 181 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 212 + leapYear) && (days <= 243 + leapYear))
  {
    *month = 8;
    dayOfMonth = days - 212 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 243 + leapYear) && (days <= 273 + leapYear))
  {
    *month = 9;
    dayOfMonth = days - 243 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 273 + leapYear) && (days <= 304 + leapYear))
  {
    *month = 10;
    dayOfMonth = days - 273 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 304 + leapYear) && (days <= 334 + leapYear))
  {
    *month = 11;
    dayOfMonth = days - 304 - leapYear;
    weekDay = dayOfMonth % 7;
  }
   else if((days > 334 + leapYear) && (days <= 365 + leapYear))
  {
    *month = 12;
    dayOfMonth = days - 334 - leapYear;
    weekDay = dayOfMonth % 7;
  }

 //Based on weekDay, it will calculate a date
  switch(weekDay)
  {
    case 0: *day1 = dayOfMonth - 7 - leapYear;
                *day2 = dayOfMonth - 6 - leapYear;
                break;
    case 1: *day1 = dayOfMonth - 7 - leapYear;
                *day2 = dayOfMonth - 6 - leapYear;
                  break;
    case 2: *day1 = dayOfMonth - 7 - leapYear;
                *day2 = dayOfMonth - 6 - leapYear;
                break;
    case 3: *day1 = dayOfMonth - 7 - leapYear;
                  *day2 = dayOfMonth - 6 - leapYear;
                  break;
    case 4: *day1 = dayOfMonth - 7 - leapYear;
                  *day2 = dayOfMonth - 6 - leapYear;
                  break;
      case 5: *day1 = dayOfMonth - 7 - leapYear;
                *day2 = dayOfMonth - 6 - leapYear;
                  break;
    case 6: *day1 = dayOfMonth - 7 - leapYear;
                *day2 = dayOfMonth - 6 - leapYear;
                break;
    default: break;
  
  }
  

} //calcFallBreak

/***************************************************************************
*
*     Function Information
*
*     Name of Function: calcFallBreak
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, year, the number of days into the year that the semester starts on
*       2. int*, thanksStartDate, the calculated value of the day that thanksgiving break will start on
*       3. int*, thanksEndDate, the calculated value of the day that thanksgiving break will end on
*           4. int, leapYear, the true or false (1 or 0) value of if the inputed year is a leap year
*   
*     Function Description: This function will calculate the date of Thanksgiving break using the semester start date.
*
***************************************************************************/
void calcThanksgiving(int year, int leapYear, int* thanksStartDate, int* thanksEndDate)
{
//Local Declarations
  int yearStart;
  int novStart;
  int yearEnd;
  int a;
  int b;
  int c;
  int d;
  int final;
  
//Statements
  a = ((year - 1) * 365); 
  b = ((year - 1) / 4);
  c = (year - 1) / 100;
  d = ((year - 1) / 400);
  final = a + b - c + d;
  yearEnd = final % 7;
 
  //Switches yearEnd to one value forward so that it equals the day of the week that the first day of the next year starts
  switch(yearEnd)
  {
    case 0: yearStart = 1;
                break;
    case 1: yearStart = 2;
                break;
    case 2: yearStart = 3;
                break;
    case 3: yearStart = 4;
                break;
    case 4: yearStart = 5;
                break;
    case 5: yearStart = 6;
                break;
    case 6: yearStart = 0;
                break;
    default: break;
  }
  
  //depending on yearStart, calculates the day of the week november starts on
  switch(yearStart) 
  {
    case 0: novStart = 304 % 7; 
              break;
    case 1: novStart = 305 % 7;
                break;
    case 2: novStart = 306 % 7;
                break;
    case 3: novStart = 307 % 7;
                break;
    case 4: novStart = 308 % 7;
                break;
    case 5: novStart = 309 % 7;
                break;
    case 6: novStart = 310 % 7;
                break; 
    default: break;
  }
  
  //based on novStart, calculates the dates of break using formula
   switch(novStart)
  {
    case 0: *thanksStartDate = 31 - (334 + leapYear - (304 + 24)); //
                *thanksEndDate = 31 - (334 + leapYear - (304 + 26)); 
                break;
            
    case 1: *thanksStartDate = 31 - (334 + leapYear - (304 + 23));
              *thanksEndDate = 31 - (334 + leapYear - (304 + 25));
                break;
            
    case 2: *thanksStartDate = 31 - (334 + leapYear - (304 + 22));
                *thanksEndDate = 31 - (334 + leapYear - (304 + 24));
                break;
            
    case 3: *thanksStartDate = 31 - (334 + leapYear - (304 + 21)); 
              *thanksEndDate = 31 - (334 + leapYear - (304 + 23));
                break;
            
      case 4: *thanksStartDate = 31 - (334 + leapYear - (304 + 20));
                *thanksEndDate = 31 - (334 + leapYear - (304 + 22));
                  break;
            
      case 5: *thanksStartDate = 31 - (334 + leapYear - (304 + 26));
                *thanksEndDate = 31 - (334 + leapYear - (304 + 28));
                  break;
            
      case 6: *thanksStartDate = 31 - (334 + leapYear - (304 + 25));
                *thanksEndDate = 31 - (334 + leapYear - (304 + 27));
                  break;
    default: break;
  }
    return;
} //calcThanksgiving

/***************************************************************************
*
*     Function Information
*
*     Name of Function: printResults
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, year, the given year from the user
*       2. int, startMonth, the month of the semester start date
*       3. int, dayOfMonth, the day of the month that the semester starts on
            4. int, year, the given year
            5. int, day1, the first day of fall break
            6. int, day2, the second day of fall break
            7. int, thanksStartDate, the start of thanksgiving break
            8. int, thanksEndDate, the end of thanksgiving break
*
*     Function Description: This function will print the series of statements (the semester start, october break, and thanksgiving break) 
*
***************************************************************************/
void printResults(month, startMonth, dayOfMonth, year, day1, day2, thanksStartDate, thanksEndDate)
{
  printf("Semester start date:  %02d/%02d/%d\n", startMonth, dayOfMonth, year);
  printf("October Break %d:  %02d/%02d - %02d/%02d\n", year, month, day1, month, day2);
  printf("Thanksgiving break %d: 11/%02d - 11/%02d\n", year, thanksStartDate, thanksEndDate);
  return;
} //printResults

/***************************************************************************
*
*     Function Information
*
*     Name of Function: printResults
*
*     Programmer's Name: Erica Liu
*
*     Function Return Type: void
*
*     Parameters (list data type, name, and comment one per line):
*       1. int, year, the given year from the user
*       2. int, startMonth, the month of the semester start date
*       3. int, dayOfMonth, the day of the month that the semester starts on
*
*     Function Description: This function will print the default print statement if the given day number of the fall semester does not fall on a monday
*
***************************************************************************/
void printDefault(startMonth, dayOfMonth, year)
{
  printf("The date:  %02d/%02d/%d does not fall on Monday.\n", startMonth, dayOfMonth, year);
  return;
} //printDefault

  

HW #4

For this program, the user is prompted to give a year and day number of that year on which the fall semester begins. Using that information, the program will calculate the calendar date of the start of the semester (must be Monday), when October Break will take place (Monday and Tuesday of the 8th week of the semester), and when the Thanksgiving Break (fourth Thursday in November, day before and after included in the break) will occur.