关于C++的问题，需要编译

编写一下这个几个程序，不用标写注释，每个程序前面都要标清楚题号 9.1～9.3

9.1

#include <iostream>
using namespace std;
const size = 10;
void findmax(int* a, int n, int &pk);

int main()
{
    int a[size];
    int n = 0;
    cout < "plsease input " << size << "datas:\n";
    for (int i = 0; i < size; i++)
    {
        cin >> a[i];
    }
    findmax(a, size, n);
    cout << "the maximum is " << a[n] << endl << "It's index is " << n << endl;

}

void findmax(int* a, int n, int& pk)
{
    pk = 0;
    for (int i = 1; i < n; i++)
    {
        if (a[i] > a[pk])
            pk = i;
    }
}

大学生请自行解决编程作业！