std::sort
Defined in header
<algorithm>
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template< class RandomIt >
void sort( RandomIt first, RandomIt last ); |
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template< class RandomIt, class Compare >
void sort( RandomIt first, RandomIt last, Compare comp ); |
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Sorts the elements in the range [first, last)
in ascending order. The order of equal elements is not guaranteed to be preserved. The first version uses operator< to compare the elements, the second version uses the given comparison function object comp
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[edit] Parameters
first, last | - | the range of elements to sort |
comp | - | comparison function object (i.e. an object that satisfies the requirements of Compare ) which returns true if the first argument is less than (i.e. is ordered before) the second. The signature of the comparison function should be equivalent to the following: bool cmp(const Type1 &a, const Type2 &b); The signature does not need to have const &, but the function object must not modify the objects passed to it. |
Type requirements | ||
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RandomIt must meet the requirements of ValueSwappable and RandomAccessIterator .
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-The type of dereferenced RandomIt must meet the requirements of MoveAssignable and MoveConstructible .
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Compare must meet the requirements of Compare .
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[edit] Return value
(none)
[edit] Complexity
O(N·log(N)), where N = std::distance(first, last) comparisons on average. |
(until C++11) |
O(N·log(N)), where N = std::distance(first, last) comparisons. |
(since C++11) |
[edit] Example
#include <algorithm> #include <functional> #include <array> #include <iostream> int main() { std::array<int, 10> s = {5, 7, 4, 2, 8, 6, 1, 9, 0, 3}; // sort using the default operator< std::sort(s.begin(), s.end()); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a standard library compare function object std::sort(s.begin(), s.end(), std::greater<int>()); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a custom function object struct { bool operator()(int a, int b) { return a < b; } } customLess; std::sort(s.begin(), s.end(), customLess); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a lambda expression std::sort(s.begin(), s.end(), [](int a, int b) { return b < a; }); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; }
Output:
0 1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0
[edit] See also
sorts the first N elements of a range (function template) |
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sorts a range of elements while preserving order between equal elements (function template) |
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(parallelism TS)
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parallelized version of std::sort (function template) |