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C++ || Struct – Add One Second To The Clock Using A Struct

January 08, 2012 admin No comments

Here is another actual homework assignment which was presented in an intro to programming class. This program utilizes a struct, which is very similar to the class concept. For this assignment, the class was asked to make a program which prompted the user to enter a time in HH:MM:SS (Hours:Minutes:Seconds) format. Upon obtaining the time from the user, our class was asked to use a struct implementation which was to simply add one second to the time that was entered by the user. Seems easy enough, though I initially had afew problems when starting the program.

This page will be very brief in its breakdown of the program’s code, as it is already heavily commented. The code is basically unchanged from the code which was turned in for grading.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Functions Passing a Value By Reference Structures Constant Variables Boolean Expressions Setw

NOTE: On some compilers, you may have to add #include < cstdlib> in order for the code to compile.





		
		
			AddOneSecond.cpp
			
C++
			
			// ============================================================================
// File: AddOneSecond.cpp
// ============================================================================
// Description:
// This program prompts the user for the input time, then adds
// one second to the time -- if any of the time structure fields need to 
// "rollover" (e.g., the hours, minutes or seconds need to be reset to zero), 
// this function will handle that. Finally, the incremented time will be 
// displayed to stdout.
// ============================================================================
#include <iostream>
#include <iomanip>
using namespace std;

// structure declaration
struct Time
{
	int hours;
	int min;
	int sec;
};

// defined constants which do not change
// specifies the max values for each variable
const   int MAX_HOURS = 23;
const   int MAX_MINS = 59;
const   int MAX_SECS = 59;

// function prototypes
bool  IsTimeValid(Time  timeParam);
void  AddOneSecond(Time  &timeParam);
void  DisplayTime(Time  timeParam);

// ==== main ==================================================================
//
// ============================================================================
int main()
{
	Time userTime = {0,0,0}; // Initialize struct members: hrs, min, sec to 0
	char colon = ':';
	
	cout << "Please enter the time in HH:MM:SS format: ";
	cin >> userTime.hours >> colon >> userTime.min >> colon >> userTime.sec;

	// Checks to see if user entered correct data
	if (IsTimeValid(userTime) == false)
	{
       cout << "Invalid input...n" << endl;
       exit(EXIT_FAILURE);
	}

	cout << "nThe incremented time is ";
    AddOneSecond(userTime);
    DisplayTime(userTime);

	return 0;
}	// end of main

// ==== IsTimeValid ===========================================================
//
// This function will validate that the time structure contains legitimate 
// values. If this function determines that the time values are invalid, it 
// will display an error message to stdout.
// 
// Input:
//      limit [IN]  -- The users time input 
//			
// Output:
//      The Time structure as an argument to the AddOneSecond function
//
// ============================================================================
bool  IsTimeValid(Time  timeParam)
{
	// checks to see if user inputted data falls between the specified
	// const variables as declared above
	if ((timeParam.hours >= 0 && timeParam.hours <= MAX_HOURS)
		&&(timeParam.min >= 0 && timeParam.min <= MAX_MINS)
		&&(timeParam.sec >= 0 && timeParam.sec <= MAX_SECS))
	{
		return true;
	}
	else
	{
		return false;
	}
}	// end of IsTimeValid

// ==== AddOneSecond ==========================================================
//
// This function will add one second to the time
// 
// Input:
//      limit [IN]  -- The users time input 
//			
// Output:
//      The incremented time will be displayed to stdout by calling the 
//      DisplayTime function
//
// ============================================================================
void  AddOneSecond(Time  &timeParam)
{
	// this is just a simple bool which checks to see if
	// the program should increment the max hrs in the
	// 1st or 2nd if statements, which are located below
	bool incrementHrsInFirstIf = false;

	// this is just a simple bool which checks to see if
	// the program should increment the max mins in the
	// 2nd or 3rd if statements, which are located below
	bool incrementMinInSecondIf = false;

	// ========== if statement #1 - hrs ==========
	// checks to see if user selected hrs is equal to MAX
	// if it is, reset time back to 0
	if (timeParam.hours == MAX_HOURS && timeParam.min == MAX_MINS)
	{
		timeParam.hours = 0;
		incrementHrsInFirstIf = true;
	}

	// ========== if statement #2 - min ==========
	// checks to see if user selected mins is equal to MAX
	// if it is, reset time back to 0
	if (timeParam.min == MAX_MINS)
	{
		timeParam.min = 0;

		// if mins == 59, we need to increment the hrs by 1
		if(incrementHrsInFirstIf == false)
		{
			++timeParam.hours; 
		}

		incrementMinInSecondIf = true;
	}

	// ========== if statement #3 - Secs ==========
	// checks to see if user selected sec is equal to MAX
	// if it is, reset time back to 0
	if (timeParam.sec == MAX_SECS)
	{
		timeParam.sec = 0;

		// if secs == 59, we need to increment the mins by 1
		if(incrementMinInSecondIf == false)
		{
			++timeParam.min;
		}
	}
	else  // if time is not at max, increment by 1
	{
		++timeParam.sec;
	}
}	// end of AddOneSecond

// ==== DisplayTime ===========================================================
//
// This function will display the user's time
//
// Input:
//      limit [IN]  -- The users time input 
//
// Output:
//      The incremented time will be displayed 
//
// ============================================================================
void    DisplayTime(Time  timeParam)
{
	cout.fill('0');
	cout << setw(2) << timeParam.hours << ":"
		 << setw(2) << timeParam.min << ":"
		 << setw(2) << timeParam.sec 
		 << endl;
}   // http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
// File: AddOneSecond.cpp
// ============================================================================
// Description:
// This program prompts the user for the input time, then adds
// one second to the time -- if any of the time structure fields need to 
// "rollover" (e.g., the hours, minutes or seconds need to be reset to zero), 
// this function will handle that. Finally, the incremented time will be 
// displayed to stdout.
// ============================================================================
#include <iostream>
#include <iomanip>
using namespace std;
 
// structure declaration
struct Time
{
	int hours;
	int min;
	int sec;
};
 
// defined constants which do not change
// specifies the max values for each variable
const   int MAX_HOURS = 23;
const   int MAX_MINS = 59;
const   int MAX_SECS = 59;
 
// function prototypes
bool  IsTimeValid(Time  timeParam);
void  AddOneSecond(Time  &timeParam);
void  DisplayTime(Time  timeParam);
 
// ==== main ==================================================================
//
// ============================================================================
int main()
{
	Time userTime = {0,0,0}; // Initialize struct members: hrs, min, sec to 0
	char colon = ':';
	
	cout << "Please enter the time in HH:MM:SS format: ";
	cin >> userTime.hours >> colon >> userTime.min >> colon >> userTime.sec;
 
	// Checks to see if user entered correct data
	if (IsTimeValid(userTime) == false)
	{
       cout << "Invalid input...n" << endl;
       exit(EXIT_FAILURE);
	}
 
	cout << "nThe incremented time is ";
    AddOneSecond(userTime);
    DisplayTime(userTime);
 
	return 0;
}	// end of main
 
// ==== IsTimeValid ===========================================================
//
// This function will validate that the time structure contains legitimate 
// values. If this function determines that the time values are invalid, it 
// will display an error message to stdout.
// 
// Input:
//      limit [IN]  -- The users time input 
//			
// Output:
//      The Time structure as an argument to the AddOneSecond function
//
// ============================================================================
bool  IsTimeValid(Time  timeParam)
{
	// checks to see if user inputted data falls between the specified
	// const variables as declared above
	if ((timeParam.hours >= 0 && timeParam.hours <= MAX_HOURS)
		&&(timeParam.min >= 0 && timeParam.min <= MAX_MINS)
		&&(timeParam.sec >= 0 && timeParam.sec <= MAX_SECS))
	{
		return true;
	}
	else
	{
		return false;
	}
}	// end of IsTimeValid
 
// ==== AddOneSecond ==========================================================
//
// This function will add one second to the time
// 
// Input:
//      limit [IN]  -- The users time input 
//			
// Output:
//      The incremented time will be displayed to stdout by calling the 
//      DisplayTime function
//
// ============================================================================
void  AddOneSecond(Time  &timeParam)
{
	// this is just a simple bool which checks to see if
	// the program should increment the max hrs in the
	// 1st or 2nd if statements, which are located below
	bool incrementHrsInFirstIf = false;
 
	// this is just a simple bool which checks to see if
	// the program should increment the max mins in the
	// 2nd or 3rd if statements, which are located below
	bool incrementMinInSecondIf = false;
 
	// ========== if statement #1 - hrs ==========
	// checks to see if user selected hrs is equal to MAX
	// if it is, reset time back to 0
	if (timeParam.hours == MAX_HOURS && timeParam.min == MAX_MINS)
	{
		timeParam.hours = 0;
		incrementHrsInFirstIf = true;
	}
 
	// ========== if statement #2 - min ==========
	// checks to see if user selected mins is equal to MAX
	// if it is, reset time back to 0
	if (timeParam.min == MAX_MINS)
	{
		timeParam.min = 0;
 
		// if mins == 59, we need to increment the hrs by 1
		if(incrementHrsInFirstIf == false)
		{
			++timeParam.hours; 
		}
 
		incrementMinInSecondIf = true;
	}
 
	// ========== if statement #3 - Secs ==========
	// checks to see if user selected sec is equal to MAX
	// if it is, reset time back to 0
	if (timeParam.sec == MAX_SECS)
	{
		timeParam.sec = 0;
 
		// if secs == 59, we need to increment the mins by 1
		if(incrementMinInSecondIf == false)
		{
			++timeParam.min;
		}
	}
	else  // if time is not at max, increment by 1
	{
		++timeParam.sec;
	}
}	// end of AddOneSecond
 
// ==== DisplayTime ===========================================================
//
// This function will display the user's time
//
// Input:
//      limit [IN]  -- The users time input 
//
// Output:
//      The incremented time will be displayed 
//
// ============================================================================
void    DisplayTime(Time  timeParam)
{
	cout.fill('0');
	cout << setw(2) << timeParam.hours << ":"
		 << setw(2) << timeParam.min << ":"
		 << setw(2) << timeParam.sec 
		 << endl;
}   // http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

STRUCT
The structure declaration is placed above the main function, as noted on lines 16-21, containing the 3 variables (Hrs, min, sec) which are defined within the program. Line 39 displays how to access those variables from the main function, having the variable “Time userTime” as the means of access. Note, line 43, the variables can utilize cin for input.

CONST
Lines 25-27 declare the constant variables, which hold the maximum allowable time the clock is able to display. The function IsTimeValid (line 72) checks to see if user defined input is within the maximum allowable limit or not.

FILL
The program will automatically display 2 numbers for hours,mins,sec even if the user only inputted one number, as noted on lines 169-172. This is basically the same as the setfill function.

Once compiling the above code, you should receive this as your output
Note: The code was compiled five separate times to display the different outputs its able to produce

==== SAMPLE RUN #1 ==== Please enter the time in HH:MM:SS format: 0:0:25 The incremented time is 00:00:26
==== SAMPLE RUN #2 ==== Please enter the time in HH:MM:SS format: 23:58:59 The incremented time is 23:59:00 ==== SAMPLE RUN #3 ==== Please enter the time in HH:MM:SS format: 23:59:59 The incremented time is 00:00:00 ==== SAMPLE RUN #4 ==== Please enter the time in HH:MM:SS format: : : The incremented time is 00:00:01
==== SAMPLE RUN #5 ==== Please enter the time in HH:MM:SS format: 76:09:67 Invalid input...

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C++ || Struct – Add One Second To The Clock Using A Struct

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