C programming langue

Can someone please help me to write a function in c

void printarray (int a[], int size); // print out the content of array a[] with size integers

int even(int a[], int size); // return the number of even numbers in array a[]

void insert(int a[], int size, int key, int k); // insert key into array a[] so key becomes the k-th element

void second(int a[], int size); // find the second largest number in a[] and swap it // with the first element in the array

void rearrange(int a[], int size); // rearrange array a[] so all the even numbers will // have indices less than those for the odd number

Thanks,