Sorting String ( Need help ASAP)

[Gordack]

Hello to everyone.
My Question:

struct patientlist {

char name[25];
char surname[25];
char doctor[25];
} patient[5];

I'm trying to sort these entries. User will input 5 patien's information and the programme will give the sorted results:

1. Surname ascending
2. Doctor ascending

I tried bubble sort but these are string so I couldnt sort them:

Here is the bubble sort method:

void bubbleSort(int *array, int length)
{
  int i, j, temp;
  int test; 
  for(i = length - 1; i > 0; i--)
  {
    test=0;
    for(j = 0; j < i; j++)
    {
      if(array[j] > array[j+1]) 
      {
        temp = array[j];    
        array[j] = array[j+1];
        array[j+1] = temp;
        test=1;
      }
    } 
    if(test==0) break; 
  } 
      
}

Then i had a idea of using atoi function. Can it work ? I mean i coudlnt make it work but is there a possibility?

my sample programme's output should be like that:

1. Surname ascending:

Surname Name Doctor

Jack John Marty
Kylie Johns Ken
Maale Jack Marl
Oily Jack Mika
Tyrie Katie Perty


Can u help me ?

[v0id]

Are you doing this in C or C++?
In C++ I would prefer to use a function from the STL, because it's much more secure, than coding one from the scratch by hands. I don't know if you have to do the function by hand, or you can choose by yourself?

Example using the STL sort() from algorithm:

#include <iostream>
#include <algorithm> // sort()

int main()
{
	int arr[]   = {5, 3, 4, 1, 2}; // Gonna be: 1 2 3 4 5
	int arrSize = 4;
	
	std::cout << "Before sort()" << std::endl;
	for(int i = 0; i <= arrSize; i++)
		std::cout << arr[i] << std::endl;
		
	std::sort(arr, arr+arrSize+1);
		
	std::cout << "After sort()" << std::endl;
	for(int j = 0; j <= arrSize; j++)
		std::cout << arr[j] << std::endl;
		
	return 0;
}

[Gordack]

Originally Posted by v0id

Are you doing this in C or C++?
In C++ I would prefer to use a function from the STL, because it's much more secure, than coding one from the scratch by hands. I don't know if you have to do the function by hand, or you can choose by yourself?

Example using the STL sort() from algorithm:

#include <iostream>
#include <algorithm> // sort()

int main()
{
	int arr[]   = {5, 3, 4, 1, 2}; // Gonna be: 1 2 3 4 5
	int arrSize = 4;
	
	std::cout << "Before sort()" << std::endl;
	for(int i = 0; i <= arrSize; i++)
		std::cout << arr[i] << std::endl;
		
	std::sort(arr, arr+arrSize+1);
		
	std::cout << "After sort()" << std::endl;
	for(int j = 0; j <= arrSize; j++)
		std::cout << arr[j] << std::endl;
		
	return 0;
}

I'm trying to do this in C language.

[v0id]

I can't really help you out then. I'm not very good with algorithms and I don't have the time to try to make it work.

I can probably help you out with some theory.
You've to send the whole array of patientlist's (patient) to the function, else it will not have anything to compare. The example you have made (bubbleSort()) does not sort multiple arrays, only one! In your patientlist-structure, you have array of strings - and it isn't those array that have to be sorted, it is the array of arrays, if we can say it in that way. That's the reason why you have to send the whole array of patientlist's to the function. When that is said, you have to use something similar to the example you came with. Compare each character, for one or two, or maybe them all in one time, and then exchange the strings - but do not forget to exchange the other strings in the array too, they belong the exchanged string.

To make it a bit clearer, look at this...

int x, y;

for(x = 0; x < 5; x++)
{
    for(y = 0; y < strlen(patient[x].surname); y++)
    {
        /* 

            We can now compare patient[x].surname[y] with 
            patient[x].surname[y+1]. Each of them contains a
            character. And of course, when it's in ascending
            order, you're gonna compare using the '<' operator.
            That's because the smallest value (ASCII) is going
            to be the first in the array.

        */
    }
}

Hope you understood just a bit.
Good luck!

[WingedPanther]

You're looking at needing two things:
1) you need a string copy function and a string compare function
2) you will need a temporary variable to hold values in.

What you need to do is use the string compare function to compare the strings, and a copy function with the temporary string to perform a swap. Once you have those, you should be able to modify the bubble sort to accomplish what you want.