how to find the max of a vectory in cpp code example

Example 1: max of a vector c++

cout<<*max_element(a.begin(), a.end())<<endl;

Example 2: c++ max and min of vector

template <typename T, size_t N> const T* mybegin(const T (&a)[N]) { return a; }    
template <typename T, size_t N> const T* myend  (const T (&a)[N]) { return a+N; }