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max_element
function template
<algorithm>
template <class ForwardIterator>
ForwardIterator max_element ( ForwardIterator first, ForwardIterator last );
template <class ForwardIterator, class Compare>
ForwardIterator max_element ( ForwardIterator first, ForwardIterator last,
Compare comp );
Return largest element in range
Returns an iterator pointing to the element with the largest value in the range [first,last). The comparisons are performed using either operator< for the first version, or comp for the second; An element is the largest if it does not compare less than any other element (it may compare equal, though).
The behavior of this function template is equivalent to:
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template <class ForwardIterator>
ForwardIterator max_element ( ForwardIterator first, ForwardIterator last )
{
ForwardIterator largest = first;
if (first==last) return last;
while (++first!=last)
if (*largest<*first) // or: if (comp(*largest,*lowest)) for the comp version
largest=first;
return largest;
}
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Parameters
- first, last
- Input iterators to the initial and final positions of the sequence to use. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
- comp
- Comparison function object that, taking two values of the same type than those contained in the range, returns true if the first argument is to be considered less than the second argument, and false otherwise.
Return value
Iterator to largest value in the range.
Example
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// min_element/max_element
#include <iostream>
#include <algorithm>
using namespace std;
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:
cout << "The smallest element is " << *min_element(myints,myints+7) << endl;
cout << "The largest element is " << *max_element(myints,myints+7) << endl;
// using function myfn as comp:
cout << "The smallest element is " << *min_element(myints,myints+7,myfn) << endl;
cout << "The largest element is " << *max_element(myints,myints+7,myfn) << endl;
// using object myobj as comp:
cout << "The smallest element is " << *min_element(myints,myints+7,myobj) << endl;
cout << "The largest element is " << *max_element(myints,myints+7,myobj) << endl;
return 0;
}
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The example illustrates how the comparison object can be either a function or an object whose class defines the operator() member. In this case both have been defined to perform a standard less-than comparison.
Output:
The smallest element is 2
The largest element is 9
The smallest element is 2
The largest element is 9
The smallest element is 2
The largest element is 9
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Complexity
Linear: Performs as many comparisons as the number of elements in [first,last), except for first.
See also
| min_element | Return smallest element in range (function template) |
| upper_bound | Return iterator to upper bound (function template) |
| max | Return the greater of two arguments (function template) |
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