根据结构成员对结构的指针数组进行排序-最佳选择？

Question

I have the following struct:

typedef struct details clientDetails;
struct details 
{
    int socket;  
    char* port;
    char* IP;
    char* hostName;
    int msgSentCount;
    int msgRecvCount;
    char* status;
    char* bufferMsg;
    char* blockedUser[4];
    int blockedCount;   
};

And I have the following array of pointers to the struct:

clientDetails* allClients[4];

What would be the best possible way to keep the array sorted by the port number of the struct?

The implementation required would be as follows:

sortByPort(allClients) -> passes a reference to the array and sorts it so that if I print the values of allClients after this function call, I will have it sorted by the port number.

Answer 1

The problem is based on which sorting algorithm suits best in your application. It could be, quick sort, merge sort, or a simple selection sort. As your example the length of the array is just 4, I've made an example with selection sort:

clientDetails * sortByPort(clientDetails *pClients, size_t len)
{
   size_t i, k;

   for (i = 0; i < len - 1; ++i) {
      size_t k = i;

      for (j = i + 1; j < len; ++j) {
         if (atoi(pClients[j].port) < atoi(pClients[k].port)) {
            k = j;
         }
      }

      clientDetails *tmp = pClients[k];
      pClients[k] = pClients[i];
      pClients[i] = tmp;
   }

   return pClients;
}

You can use strtol instead of atoi if the port is greater than an int value.