passing array to a function in C Programming

Question

#include <stdio.h>
int find(int arr[4]);

int main()
{
    int arr[4] = {1,2,3,4};
    int s;
    s = find(arr);
    printf("%d", s);

    return 0;
}

int find(int arr[4])
{
    int n = sizeof(arr) / sizeof(arr[0]);
    return n;
}

in the code above what is wrong. please help me out :(

I tried to run in gcc compiler but getting array declaration error.