c++学习

#include <iostream>
#include <cmath>
void evaluation()
{
    int i=0, j, sum=0, max=0, min=0;    
    std::cout << "请输入20个数";
    std::cin >> i;
    max = i;
    min = i;
    sum += i;
    for (j=0;j<20;j++)
    {
        std::cin >> i;
        sum += i;
        if (i>max)
        {
            max = i;
        }
        if (i<min)
        {
            min = i;
        }
    }
    std::cout <<"最小值:"<< min<<"最大值:"<<max << "平均值:"<< (double)sum/20<<std::endl;    
}

印度国王的奖励

void king()
{
    unsigned long long i=0;
    unsigned long long sum = 0;
    for (int j = 0; j < 64; j++)
    {
        sum =sum +(unsigned long long)2 >> j;
    }
    std::cout << sum-1 << std::endl;
}