c++ - 同时最小值和最大值

Question

我尝试实现一种算法，该算法将在给定数组中搜索最小和最大元素，并使用了 Cormen 的算法简介 中的思想。我的代码编译并开始工作，输出生成的随机数组，然后很长一段时间什么都不做。为什么会这样？

代码是这样的:

// fast min and max --cormen exercise 1.cpp: entry point
//implemented from a verbal description in cormen's book, p 243

#include "stdafx.h"
#include <vector>
#include <ctime>
#include <cstdlib>
#include <iostream>

struct min_and_max
{
    int min, max;
};


min_and_max find_min_and_max(std::vector<int>& A)
{
    int n = A.size();
    int min, max;
    if (n%2 == 1)
        min = max = A[0];
    if (n%2 == 0)
        if (A[0] < A[1])
        {
            min = A[0];
            max = A[1];
        }
        else
        {
            min = A[1];
            max = A[0];
        }
    for(int i = 2; i < A.size(); (i + 2))
    {
        if (A[i] < A[i+1])
        {
            if (min > A[i])
                min = A[i];
            if (max < A[i+1])
                max = A[i+1];
        }
        else
        {
            if (min > A[i+1])
                min = A[i+1];
            if (max < A[i])
                max = A[i];
        }
    }
    min_and_max result;
    result.min = min;
    result.max = max;

    return result;
}

int main()
{
    std::srand(std::time(0));
    std::vector<int> A(10);
    for (auto i = 0; i < A.size(); i++)
        {
            A[i] = rand() % 1000;
            std::cout << A[i] << " ";           
        }
    std::cout << std::endl; //IT GOES AS FAR AS THIS
    std::cout << "The array has been analyzed; its' minimum is " << find_min_and_max(A).min << "and its' maximum is " << find_min_and_max(A).max << std::endl;

    return 0;
}

Answer 1

 for(int i = 2; i < A.size(); (i + 2))

i + 2不会改变i的值，你需要使用i += 2。