Sort using comparator

[Phoenix_X.0]

bool compare(int a, int b)
{return a>b}

int arr[n]={1, 3, 2, 2, 7, 5, 4, 6}
sort(arr, arr+n, compare);

What arguments are passed to the compare function by the sort STL function? Is it the 1st and the 2nd element of the array?

[anon72424297]

Hello too!
Let me Google that for you…
Here you are: https://www.cplusplus.com/reference/algorithm/sort/
Have a nice day!

[pardouin]

The compare function explains on which criteria you want your values to be ordered.
More precisely, given two values a and b, it must return if you consider that a must be ranked higher than b.
The default sort ranks a higher than b if a > b but you can imagine other possibilities:

• rank a higher than b if a*a > b*b (sort by absolute value)
• rank a higher than b if arr2[a] > arr2[b] where arr2 is another array
• rank a higher than be if f(a) > f(b) where f is a function (f is called an “evaluation function” in this case)

[anon72424297]

Thank you Google…