程序代码：

#include <iostream>
#include <cstring>
using namespace std;
template <class T>
T maxn(T arr[], int n)
{
    T max = arr[0];
    for (int i = 0; i < n; ++i)
    {
        if (arr[i] > max)
        {
            max = arr[i];
        }
    }
    return max;
}
template <> char* maxn<char*>(char* pa[], int n)
{
    int MaxLen = strlen(pa[0]);
    for (int i = 0; i < n; ++i)
    {
        if (strlen(pa[i]) > MaxLen)
        {
            MaxLen = strlen(pa[i]);
        }
    }
    return pa[i];
}

int main(void)
{
    int test[3] = {1,2,4};
    double dtest[3] = {1.1,2.2, 3};
    char* ptest[3] = {"first blood", "double kill", "triple kill"};
    cout << "func1 :" << maxn(test,3) << endl;
    cout << "func2 :" << maxn(dtest,3) << endl;
    cout << "func3 :" << maxn(ptest,3) << endl;

    return 0;
}