Question

struct Record
{
    char Surname[20];
    char Initial;
    unsigned short int Gender; //0 = male | 1 = female
    unsigned short int Age;
};
Record X[100];

How can I use Quicksort to sort the values into increasing age, with females before males and surnames in alphabetical order? I’ve got a:

bool CompareData(const int& A, const int& B)
{
    return Records[A].Age < Records[B].Age; //this sorts by age atm
}

Answer 1

bool CompareData(const int& A, const int& B)
{
    return (Records[A].Age < Records[B].Age) ||
           ((Records[A].Age == Records[B].Age) && (Records[A].Gender > Records[B].Gender)) || 
           ((Records[A].Age == Records[B].Age) && (Records[A].Gender == Records[B].Gender) &&
              (strcmp(Records[A].Surname, Records[B].Surname) < 0));
}

This compares first by age and returns true if A should appear before B based on age.

If ages are equal, it then compares by gender, and returns true if A should appear before B based on gender (A is female and B is male).

If ages are equal and genders are equal, it then compares by surname (using strcmp, although if you had used std::string instead of a char array, you could have just used <), and returns true if A should appear before B alphabetically by surname.