Re: how to make a functor for min_element
Am 15.01.2011 23:17, schrieb terminator:
[..]
I tried to find the minimal element in a vector, in case
of equality, randomly choose the one of minimal elements.
How to implement it by using std::min_element ?
Thank you in advance.
Happy new year,
Jun
If the vector contains more than one copy of the minimum element, the
iterator points to the first occurrence of the minimum element
code fragments below
typedef std::vector<int, std::allocator<int> > vec_elm;
const vec_elm::value_type v1[] = { 1, 1, 2, 3, 5, 8 };
vec_elm vec(v1 + 0, v1 + sizeof v1 / sizeof *v1);// create vector
vec_elm::iterator itr = std::min_element (vec.begin(), vec.end());//
search for the first smallest element
std::cout<< *itr; //print the answer, ie vec[0]
Would this not do?
{
int v1[] = { 1, 1, 2, 3, 5, 8 };
int* wh = std::min_element (v1,v1+sizeof v1/sizeof int);
std::cout<< *wh;
}
Sure, but the OP asked for finding the minimum element in a *vector*, not in an array (It doesn't make a difference, though).
Dosen`t the function accept raw pointers as bidirectional iterators?
std::min_element even works for forward iterators.
I'm still unsure what *precisely* has been the intention of the OP's request. The exact question
"in case of equality, randomly choose the one of minimal elements"
can be interpreted to really ask for an algorithm that
a) determines all equivalent minimum elements, and
b) performs a random shuffle step (according to which randomness criteria?) among these elements to select one randomly.
Greetings from Bremen,
Daniel Kr?gler
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