https://blog.csdn.net/breeze5428/article/details/25918925

参考网页：

http://en.cppreference.com/w/cpp/algorithm/min_element

主要有两种用法

template< class ForwardIt > 
ForwardIt min_element( ForwardIt first, ForwardIt last );

template< class ForwardIt, class Compare >
ForwardIt min_element( ForwardIt first, ForwardIt last, Compare comp );

// min_element/max_element example
#include <iostream>     // std::cout
#include <algorithm>    // std::min_element, std::max_element
 
bool myfn(int i, int j) { return i<j; }
 
struct myclass {
  bool operator() (int i,int j) { return i<j; }
} myobj;
 
int main () {
  int myints[] = {3,7,2,5,6,4,9};
 
  // using default comparison:
  std::cout << "The smallest element is " << *std::min_element(myints,myints+7) << '\n';
  std::cout << "The largest element is "  << *std::max_element(myints,myints+7) << '\n';
 
  // using function myfn as comp:
  std::cout << "The smallest element is " << *std::min_element(myints,myints+7,myfn) << '\n';
  std::cout << "The largest element is "  << *std::max_element(myints,myints+7,myfn) << '\n';
 
  // using object myobj as comp:
  std::cout << "The smallest element is " << *std::min_element(myints,myints+7,myobj) << '\n';
  std::cout << "The largest element is "  << *std::max_element(myints,myints+7,myobj) << '\n';
 
  return 0;
}