Question

Write a C++ program accepts a three-integer date in the following formats: mm/dd/yyyy or mm-dd-yyyy. Write a Boolean function that validates the date. Note: account for leap years. After testing with single dates and verifying the algorithm works, set your program up to accept a file called dates.dat. Read the dates into your program and output bad dates to a file called bad_dates.dat.

Answer 1

#include <iostream>

#include <fstream>

#include <string>

using namespace std;

//date type structure

struct date

{

    int dd;

    int mm;

    int yyyy;

};

//return true if year is a leap year

bool isLeapYear(int year)

{

    return (((year % 4 == 0) &&  (year % 100 != 0)) || (year % 400 == 0));

}

bool checkDate(int dd, int mm, int yyyy)

{

    // check if year is between 1800 and 9999

    if (yyyy > 9999 ||  yyyy < 1800)

        return false;

    if (dd < 1 || dd > 31)

        return false;

    if (mm < 1 || mm > 12)

        return false;

   

    

  

    // for even months date cannot be greater than 30

    if (mm == 4 || mm == 6 || mm == 9 || mm == 11)

        return (dd <= 30);

    //For february month

    if (mm == 2)

    {

        if (isLeapYear(yyyy))

        return (dd <= 29);

        else

        return (dd <= 28);

    }

  

    return true;

}

int main(){

    //input file

    fstream file;

    file.open("dates.dat",ios::in|ios::binary);

    //output file

    ofstream outFile;

    outFile.open("bad_dates.dat", ios::binary | ios::app);

    

    //check if any error while opening file

    if(!outFile || !file ){

        cout<<"cannot open file"<<endl;

        return 1;

    }

    //date object for read and write of dates

    date d;

    file.read((char*)&d,sizeof(date));

    while(file){

        

        //check if date is not valid then write in bad_date.dat

        if(!checkDate(d.dd, d.mm, d.yyyy))

            outFile.write((char*)&d, sizeof(date));

        

    file.read((char*)&d,sizeof(date));

    }

    outFile.close();

    return 0;

}