Difference between revisions of "cpp/algorithm/sort"
m (r2.7.3) (Robot: Adding de, es, fr, it, ja, pt) |
(added a few other comparison methods) |
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| Line 42: | Line 42: | ||
int main() | int main() | ||
{ | { | ||
| − | std::array<int, 10> s{5, 7, 4, 2, 8, 6, 1, 9, 0, 3}; | + | 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()); | std::sort(s.begin(), s.end()); | ||
for (int a : s) { | for (int a : s) { | ||
std::cout << a << " "; | std::cout << a << " "; | ||
| − | } | + | } |
std::cout << '\n'; | std::cout << '\n'; | ||
| + | // sort using a standard library compare function | ||
std::sort(s.begin(), s.end(), std::greater<int>()); | std::sort(s.begin(), s.end(), std::greater<int>()); | ||
| + | for (int a : s) { | ||
| + | std::cout << a << " "; | ||
| + | } | ||
| + | std::cout << '\n'; | ||
| + | |||
| + | // sort using a custom functor | ||
| + | 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 | ||
| + | std::sort(s.begin(), s.end(), [](int a, int b) { | ||
| + | return b < a; | ||
| + | }); | ||
for (int a : s) { | for (int a : s) { | ||
std::cout << a << " "; | std::cout << a << " "; | ||
} | } | ||
std::cout << '\n'; | std::cout << '\n'; | ||
| − | } | + | } |
| output= | | output= | ||
| − | 0 1 2 3 4 5 6 7 8 9 | + | 0 1 2 3 4 5 6 7 8 9 |
| − | 9 8 7 6 5 4 3 2 1 0 | + | 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 | ||
}} | }} | ||
Revision as of 07:17, 20 January 2013
Template:ddcl list begin <tr class="t-dsc-header">
<td><algorithm>
<td></td> <td></td> </tr> <tr class="t-dcl ">
<td >void sort( RandomIt first, RandomIt last );
<td > (1) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td >void sort( RandomIt first, RandomIt last, Compare comp );
<td > (2) </td> <td class="t-dcl-nopad"> </td> </tr> Template:ddcl list end
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 comp.
Contents |
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 the second. The signature of the comparison function should be equivalent to the following: bool cmp(const Type1& a, const Type2& b); While the signature does not need to have const&, the function must not modify the objects passed to it and must be able to accept all values of type (possibly const) |
| Type requirements | ||
-RandomIt must meet the requirements of ValueSwappable and LegacyRandomAccessIterator.
| ||
-The type of dereferenced RandomIt must meet the requirements of MoveAssignable and MoveConstructible.
| ||
Return value
(none)
Complexity
O(N·log(N)), where N = std::distance(first, last) applications of cmp.
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 std::sort(s.begin(), s.end(), std::greater<int>()); for (int a : s) { std::cout << a << " "; } std::cout << '\n'; // sort using a custom functor 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 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
