max_element（min_element）

Copyright: code word is not easy, please indicate the source: https://blog.csdn.net/qq_24309981/article/details/90578276

Theory 1

Include files: #include <algorithm>
Namespace: a using namespace std;
function template:

template <class ForwardIterator>
ForwardIterator max_element (ForwardIterator first, ForwardIterator last);
template <class ForwardIterator, class Compare>
ForwardIterator max_element (ForwardIterator first, ForwardIterator last, Compare comp);

功能： Return largest element in range

• Returns an iterator pointing to the element with the largest value in the range [first,last), or last if the range is empty;
• The comparisons are performed using either operator< for the first version, or comp for the second;
• If more than one element fulfills this condition, the iterator returned points to the first of such elements.

The behavior of this function template is equivalent to:

template <class ForwardIterator>
ForwardIterator max_element ( ForwardIterator first, ForwardIterator last )
{
	if (first==last) return last;
	ForwardIterator largest = first;
	while (++first!=last)
    if (*largest<*first)    // or: if (comp(*largest,*first)) for version (2)
		largest=first;
	return largest;
}

Example 2

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
	vector<int> nums = { 1,2,3,4,5,6,7,7 };
	//区间为空，返回last，即nums.begin()
	auto it = max_element(nums.begin(), nums.begin());
	cout << *it << endl;

	it = max_element(nums.begin(), nums.end());
	//返回第一个7
	cout << *it << endl;
	it++;
	//返回第二个7
	cout << *it << endl;

	//自定义比较函数
	it = max_element(nums.begin(), nums.end(), [&](int a, int b) {return a > b; });
	cout << *it << endl;

	system("pause");
    return 0;
}
//输出
1
7
7
1

Reference 3

http://www.cplusplus.com/reference/algorithm/max_element/