Difference between revisions of "cpp/algorithm/min"

Revision as of 18:18, 2 November 2012

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<td > (1) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">

<td > (2) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">

<td > (3) </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">

<td > (4) </td> <td > (since C++11) </td> </tr> Template:ddcl list end

1-2) Returns the smaller of the two values.

3-4) Returns the smallest of the values in initializer list ilist.

The (1,3) versions use operator< to compare the values, the (2,4) versions use the given comparison function comp.

Parameters

Return value

1-2) The smaller of a and b. If the values are equivalent, returns a.

3-4) The smallest value in ilist. If several values are equivalent to the smallest, returns the leftmost such value.

Complexity

1-2) Constant

3-4) Linear in ilist.size()

Possible implementation

template<class T> 
const T& min(const T& a, const T& b)
{
    return (a < b) ? a : b;
}

template<class T, class Compare> 
const T& min(const T& a, const T& b, Compare comp)
{
    return (comp(a, b)) ? a : b;
}

template<class T>
T min( std::initializer_list<T> ilist)
{
    return *std::min_element(ilist.begin(), ilist.end());
}

template<class T, class Compare>
T min(std::initializer_list<T> ilist, Compare comp)
{
    return *std::min_element(ilist.begin(), ilist.end(), comp);
}

Example

#include <algorithm>
#include <iostream>
 
int main()
{
    std::cout << "smaller of 1 and 9999: " << std::min(1, 9999) << '\n';
    std::cout << "smaller of 'a' and 'b': " << std::min('a', 'b') << '\n';
    std::cout << "smaller of 3.5 and 2.5: " << std::min(3.5, 2.5) << '\n';
}

smaller of 1 and 9999: 1
smaller of 'a' and 'b': a
smaller of 3.5 and 2.5: 2.5

See also