如何编写一个函数让其可返回数组下标？

如何设计一个函数，使其可以返回存储在double类型数组中最大值的下标

#include <stdio.h>

#define N 10

int find_max_element(double *a, int n)
{
    if (!a || n <= 0)
        return -1;
    double max = a[0];
    int i = 0;
    for (int j = 1; j < n; j++)
    {
        if (a[j] > max)
        {
            max = a[j];
            i = j;
        }
    }
    return i;
}

int main()
{
    double a[N] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
    printf("%d", find_max_element(a, N));
    return 0;
}

double[] values = {...};
int size = sizeof(values) / sizeof(double);

int getMaxIndex(double *values, int size)
{
double max = 0.0;
int idx = 0;
for (int i = 0; i < size; ++i)
{
if (values[i] > max)
{
max = values[i];
idx = i;
}
}
return idx;
}