Using selection sort to sort a list based on player points?

Question

I am trying to sort a list from a binary file of players hockey stats. My goal is to use selection sort algorithm to sort the list in a descending order based on number of points in a game where points = goals + assists.

I am using an array of structures where each array is a structure of the players stats.

Here is the structure.

struct Player
{
 char name[20];
 int goals;
int assists;
int rating;
};

This is what I have in my sort array function so far.

 void sortArrays( Player players[], int numPlayers)
int top=0;
int ssf;
int last=numPlayers;
int ptr;
int i = 0;
Player temp;

while (top < last)    
{
    ptr=top;
    ssf=top;

    pnts = players[i].goals + players[i].assists;
    i++;
}

After this I am stuck.

Here are the steps the function is suppose to perform in broad terms.

1. Calculate number of points by using the formula points = player[i].goals + player[i].assists

2. Sort the array of structures in descending order based on number of points.

3. Swap the different arrays until the list is sorted in a descending order based on greatest amount of points to least.

Answer 1

Do you have to use selection sort? You could use std::sort instead if you define a custom comparison function:

bool compare_players(Player const& a, Player const& b) {
  return (b.goals + b.assists) < (a.goals + a.assists);
}

Then throw your players into a vector called players and just

std::sort(players.begin(), players.end(), &compare_players);

This is less code and it's also more efficient (O(n log n)) than implementing a selection sort (O(n^2)).