编写重载函数可求取2个整数，3个整数的最大值

下面给出两种方案：

方案一：使用函数重载实现

#include <iostream>
using namespace std;

int max(int a, int b) {
    return (a > b) ? a : b;
}

int max(int a, int b, int c) {
    int max1 = max(a, b);
    int max2 = max(max1, c);
    return max2;
}

int main() {
    int a = 1, b = 2, c = 3;
    cout << "max(a,b) = " << max(a, b) << endl;
    cout << "max(a,b,c) = " << max(a, b, c) << endl;
    return 0;
}

方案二：使用可变参数模板实现

#include <iostream>
#include <cstdarg>
using namespace std;

int max(int count, ...) {
    int res = INT_MIN;
    va_list vl;
    va_start(vl, count);
    for (int i = 0; i < count; ++i) {
        int val = va_arg(vl, int);
        res = (val > res) ? val : res;
    }
    va_end(vl);
    return res;
}

int main() {
    int a = 1, b = 2, c = 3;
    cout << "max(a,b) = " << max(2, a, b) << endl;
    cout << "max(a,b,c) = " << max(3, a, b, c) << endl;
    return 0;
}

这两种方案都可以用来求取2个整数和3个整数的最大值，使用哪种方案取决于具体的需求情况。