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Algorithms library

From cppreference.com
< cpp
 
 
Algorithm library
Execution policies (C++17)
Non-modifying sequence operations
(C++11)(C++11)(C++11)
(C++17)
Modifying sequence operations
Operations on uninitialized storage
Partitioning operations
Sorting operations
(C++11)
Binary search operations
Set operations (on sorted ranges)
Heap operations
(C++11)
Minimum/maximum operations
(C++11)
(C++17)
Permutations
Numeric operations
C library
 

The algorithms library defines functions for a variety of purposes (e.g. searching, sorting, counting, manipulating) that operate on ranges of elements. Note that a range is defined as [first, last) where last refers to the element past the last element to inspect or modify.

Contents

Constrained algorithms

C++20 provides constrained versions of most algorithms in the namespace std::ranges. In these algorithms, a range can be specified as either an Iterator-Sentinel pair or as a single Range argument, and projections and pointer-to-member callables are supported. Additionally, the return types of most algorithms have been changed to return all potentially useful information computed during the execution of the algorithm.

The header <iterator> provides a set of concepts and related utilities designed to ease constraining common algorithm operations.

(since C++20)


Execution policies

Most algorithms have overloads that accept execution policies. The standard library algorithms support three execution policies: sequential, parallel, and parallel+vector, and the library provides corresponding execution policy types and objects. Users may select an execution policy statically by invoking a parallel algorithm with an execution policy object of the corresponding type: std::execution::seq, std::execution::par, or std::execution::par_unseq.

Standard library implementations (but not the users) may define additional execution policies as an extension. The semantics of parallel algorithms invoked with an execution policy object of implementation-defined type is implementation-defined.

Defined in header <execution>
Defined in namespace std::execution
execution policy types
(class) [edit]
(C++17)(C++17)(C++17)
global execution policy objects
(constant) [edit]
Defined in namespace std
test whether a class represents an execution policy
(class template) [edit]
(since C++17)
Non-modifying sequence operations
Defined in header <algorithm>
(C++11)(C++11)(C++11)
checks if a predicate is true for all, any or none of the elements in a range
(function template) [edit]
applies a function to a range of elements
(function template) [edit]
applies a function object to the first n elements of a sequence
(function template) [edit]
returns the number of elements satisfying specific criteria
(function template) [edit]
finds the first position where two ranges differ
(function template) [edit]
finds the first element satisfying specific criteria
(function template) [edit]
finds the last sequence of elements in a certain range
(function template) [edit]
searches for any one of a set of elements
(function template) [edit]
finds the first two adjacent items that are equal (or satisfy a given predicate)
(function template) [edit]
searches for a range of elements
(function template) [edit]
searches a range for a number of consecutive copies of an element
(function template) [edit]
Modifying sequence operations
Defined in header <algorithm>
copies a range of elements to a new location
(function template) [edit]
(C++11)
copies a number of elements to a new location
(function template) [edit]
copies a range of elements in backwards order
(function template) [edit]
(C++11)
moves a range of elements to a new location
(function template) [edit]
moves a range of elements to a new location in backwards order
(function template) [edit]
copy-assigns the given value to every element in a range
(function template) [edit]
copy-assigns the given value to N elements in a range
(function template) [edit]
applies a function to a range of elements
(function template) [edit]
assigns the results of successive function calls to every element in a range
(function template) [edit]
assigns the results of successive function calls to N elements in a range
(function template) [edit]
removes elements satisfying specific criteria
(function template) [edit]
copies a range of elements omitting those that satisfy specific criteria
(function template) [edit]
replaces all values satisfying specific criteria with another value
(function template) [edit]
copies a range, replacing elements satisfying specific criteria with another value
(function template) [edit]
swaps the values of two objects
(function template) [edit]
swaps two ranges of elements
(function template) [edit]
swaps the elements pointed to by two iterators
(function template) [edit]
reverses the order of elements in a range
(function template) [edit]
creates a copy of a range that is reversed
(function template) [edit]
rotates the order of elements in a range
(function template) [edit]
copies and rotate a range of elements
(function template) [edit]
shifts elements in a range
(function template) [edit]
(until C++17)(C++11)
randomly re-orders elements in a range
(function template) [edit]
(C++17)
selects n random elements from a sequence
(function template) [edit]
removes consecutive duplicate elements in a range
(function template) [edit]
creates a copy of some range of elements that contains no consecutive duplicates
(function template) [edit]
Partitioning operations
Defined in header <algorithm>
determines if the range is partitioned by the given predicate
(function template) [edit]
divides a range of elements into two groups
(function template) [edit]
copies a range dividing the elements into two groups
(function template) [edit]
divides elements into two groups while preserving their relative order
(function template) [edit]
locates the partition point of a partitioned range
(function template) [edit]
Sorting operations
Defined in header <algorithm>
(C++11)
checks whether a range is sorted into ascending order
(function template) [edit]
finds the largest sorted subrange
(function template) [edit]
sorts a range into ascending order
(function template) [edit]
sorts the first N elements of a range
(function template) [edit]
copies and partially sorts a range of elements
(function template) [edit]
sorts a range of elements while preserving order between equal elements
(function template) [edit]
partially sorts the given range making sure that it is partitioned by the given element
(function template) [edit]
Binary search operations (on sorted ranges)
Defined in header <algorithm>
returns an iterator to the first element not less than the given value
(function template) [edit]
returns an iterator to the first element greater than a certain value
(function template) [edit]
determines if an element exists in a certain range
(function template) [edit]
returns range of elements matching a specific key
(function template) [edit]
Other operations on sorted ranges
Defined in header <algorithm>
merges two sorted ranges
(function template) [edit]
merges two ordered ranges in-place
(function template) [edit]
Set operations (on sorted ranges)
Defined in header <algorithm>
returns true if one set is a subset of another
(function template) [edit]
computes the difference between two sets
(function template) [edit]
computes the intersection of two sets
(function template) [edit]
computes the symmetric difference between two sets
(function template) [edit]
computes the union of two sets
(function template) [edit]
Heap operations
Defined in header <algorithm>
(C++11)
checks if the given range is a max heap
(function template) [edit]
finds the largest subrange that is a max heap
(function template) [edit]
creates a max heap out of a range of elements
(function template) [edit]
adds an element to a max heap
(function template) [edit]
removes the largest element from a max heap
(function template) [edit]
turns a max heap into a range of elements sorted in ascending order
(function template) [edit]
Minimum/maximum operations
Defined in header <algorithm>
returns the greater of the given values
(function template) [edit]
returns the largest element in a range
(function template) [edit]
returns the smaller of the given values
(function template) [edit]
returns the smallest element in a range
(function template) [edit]
(C++11)
returns the smaller and larger of two elements
(function template) [edit]
returns the smallest and the largest elements in a range
(function template) [edit]
(C++17)
clamps a value between a pair of boundary values
(function template) [edit]
Comparison operations
Defined in header <algorithm>
determines if two sets of elements are the same
(function template) [edit]
returns true if one range is lexicographically less than another
(function template) [edit]
compares two values using three-way comparison
(function template) [edit]
compares two ranges using three-way comparison
(function template) [edit]
Permutation operations
Defined in header <algorithm>
determines if a sequence is a permutation of another sequence
(function template) [edit]
generates the next greater lexicographic permutation of a range of elements
(function template) [edit]
generates the next smaller lexicographic permutation of a range of elements
(function template) [edit]
Numeric operations
Defined in header <numeric>
(C++11)
fills a range with successive increments of the starting value
(function template) [edit]
sums up a range of elements
(function template) [edit]
computes the inner product of two ranges of elements
(function template) [edit]
computes the differences between adjacent elements in a range
(function template) [edit]
computes the partial sum of a range of elements
(function template) [edit]
(C++17)
similar to std::accumulate, except out of order
(function template) [edit]
similar to std::partial_sum, excludes the ith input element from the ith sum
(function template) [edit]
similar to std::partial_sum, includes the ith input element in the ith sum
(function template) [edit]
applies a functor, then reduces out of order
(function template) [edit]
applies a functor, then calculates exclusive scan
(function template) [edit]
applies a functor, then calculates inclusive scan
(function template) [edit]
Operations on uninitialized memory
Defined in header <memory>
copies a range of objects to an uninitialized area of memory
(function template) [edit]
copies a number of objects to an uninitialized area of memory
(function template) [edit]
copies an object to an uninitialized area of memory, defined by a range
(function template) [edit]
copies an object to an uninitialized area of memory, defined by a start and a count
(function template) [edit]
moves a range of objects to an uninitialized area of memory
(function template) [edit]
moves a number of objects to an uninitialized area of memory
(function template) [edit]
constructs objects by default-initialization in an uninitialized area of memory, defined by a range
(function template) [edit]
constructs objects by default-initialization in an uninitialized area of memory, defined by a start and a count
(function template) [edit]
constructs objects by value-initialization in an uninitialized area of memory, defined by a range
(function template) [edit]
constructs objects by value-initialization in an uninitialized area of memory, defined by a start and a count
(function template) [edit]
destroys an object at a given address
(function template) [edit]
(C++17)
destroys a range of objects
(function template) [edit]
(C++17)
destroys a number of objects in a range
(function template) [edit]
C library
Defined in header <cstdlib>
sorts a range of elements with unspecified type
(function) [edit]
searches an array for an element of unspecified type
(function) [edit]


[edit] See also

C documentation for Algorithms