Algorithms library

 

C++

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Freestanding and hosted

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Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Algorithm library

Constrained algorithms and algorithms on ranges (C++20)
Constrained algorithms, e.g. ranges::copy, ranges::sort, ...
Execution policies (C++17)
is_execution_policy (C++17)   execution::seqexecution::parexecution::par_unseqexecution::unseq (C++17)    (C++17)(C++17)(C++20)	execution::sequenced_policyexecution::parallel_policyexecution::parallel_unsequenced_policyexecution::parallel_unsequenced (C++17)(C++17)(C++17)(C++20)
Non-modifying sequence operations Batch operations for_each for_each_n (C++17) Search operations all_ofany_ofnone_of (C++11)                (C++11)(C++11) countcount_if mismatch equal findfind_iffind_if_not (C++11) find_end find_first_of adjacent_find search search_n Modifying sequence operations Copy operations copycopy_if (C++11) copy_backward copy_n (C++11) move (C++11) move_backward (C++11) Swap operations swap iter_swap swap_ranges Transformation operations replacereplace_if transform replace_copyreplace_copy_if Generation operations fill fill_n generate generate_n Removing operations removeremove_if unique remove_copyremove_copy_if unique_copy Order-changing operations reverse reverse_copy rotate rotate_copy random_shuffleshuffle (until C++17)(C++11) shift_leftshift_right (C++20)(C++20) Sampling operations sample (C++17)	Sorting and related operations Partitioning operations partition partition_copy (C++11)   stable_partition is_partitioned (C++11) partition_point (C++11) Sorting operations sort stable_sort partial_sort partial_sort_copy is_sorted (C++11) is_sorted_until (C++11) nth_element Binary search operations (on partitioned ranges) lower_bound upper_bound equal_range binary_search Set operations (on sorted ranges) includes set_union set_intersection set_difference set_symmetric_difference Merge operations (on sorted ranges) merge inplace_merge Heap operations push_heap pop_heap make_heap sort_heap is_heap (C++11) is_heap_until (C++11) Minimum/maximum operations max min minmax (C++11) clamp (C++17) max_element min_element minmax_element (C++11) Lexicographical comparison operations lexicographical_compare lexicographical_compare_three_way (C++20) Permutation operations next_permutation prev_permutation is_permutation (C++11) C library qsort bsearch
Numeric operations
iota (C++11) inner_product adjacent_difference    accumulate reduce (C++17) transform_reduce (C++17)	partial_sum inclusive_scan (C++17)    exclusive_scan (C++17) transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
Operations on uninitialized memory
uninitialized_copy uninitialized_move (C++17)    uninitialized_fill uninitialized_copy_n (C++11) uninitialized_move_n (C++17) uninitialized_fill_n	destroy (C++17) destroy_n (C++17) destroy_at (C++17) construct_at (C++20)       uninitialized_default_construct (C++17) uninitialized_value_construct (C++17) uninitialized_default_construct_n (C++17) uninitialized_value_construct_n (C++17)

 

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.

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 [[cpp//Range|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. std::vector<int> v = {7, 1, 4, 0, -1}; std::ranges::sort(v); // constrained 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 several execution policies, 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. 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 sequenced_policyparallel_policyparallel_unsequenced_policyunsequenced_policy (C++17)(C++17)(C++17)(C++20) execution policy types (class) seqparpar_unsequnseq (C++17)(C++17)(C++17)(C++20) global execution policy objects (constant) Defined in namespace std is_execution_policy (C++17) test whether a class represents an execution policy (class template)

(since C++17)

Non-modifying sequence operations
Defined in header <algorithm>
all_ofany_ofnone_of (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)
for_each	applies a function to a range of elements (function template)
for_each_n (C++17)	applies a function object to the first N elements of a sequence (function template)
countcount_if	returns the number of elements satisfying specific criteria (function template)
mismatch	finds the first position where two ranges differ (function template)
findfind_iffind_if_not (C++11)	finds the first element satisfying specific criteria (function template)
find_end	finds the last sequence of elements in a certain range (function template)
find_first_of	searches for any one of a set of elements (function template)
adjacent_find	finds the first two adjacent items that are equal (or satisfy a given predicate) (function template)
search	searches for the first occurrence of a range of elements (function template)
search_n	searches for the first occurrence of a number consecutive copies of an element in a range (function template)
Modifying sequence operations
Defined in header <algorithm>
copycopy_if (C++11)	copies a range of elements to a new location (function template)
copy_n (C++11)	copies a number of elements to a new location (function template)
copy_backward	copies a range of elements in backwards order (function template)
move (C++11)	moves a range of elements to a new location (function template)
move_backward (C++11)	moves a range of elements to a new location in backwards order (function template)
fill	copy-assigns the given value to every element in a range (function template)
fill_n	copy-assigns the given value to N elements in a range (function template)
transform	applies a function to a range of elements, storing results in a destination range (function template)
generate	assigns the results of successive function calls to every element in a range (function template)
generate_n	assigns the results of successive function calls to N elements in a range (function template)
removeremove_if	removes elements satisfying specific criteria (function template)
remove_copyremove_copy_if	copies a range of elements omitting those that satisfy specific criteria (function template)
replacereplace_if	replaces all values satisfying specific criteria with another value (function template)
replace_copyreplace_copy_if	copies a range, replacing elements satisfying specific criteria with another value (function template)
swap	swaps the values of two objects (function template)
swap_ranges	swaps two ranges of elements (function template)
iter_swap	swaps the elements pointed to by two iterators (function template)
reverse	reverses the order of elements in a range (function template)
reverse_copy	creates a copy of a range that is reversed (function template)
rotate	rotates the order of elements in a range (function template)
rotate_copy	copies and rotate a range of elements (function template)
shift_leftshift_right (C++20)	shifts elements in a range (function template)
random_shuffleshuffle (until C++17)(C++11)	randomly re-orders elements in a range (function template)
sample (C++17)	selects N random elements from a sequence (function template)
unique	removes consecutive duplicate elements in a range (function template)
unique_copy	creates a copy of some range of elements that contains no consecutive duplicates (function template)
Partitioning operations
Defined in header <algorithm>
is_partitioned (C++11)	determines if the range is partitioned by the given predicate (function template)
partition	divides a range of elements into two groups (function template)
partition_copy (C++11)	copies a range dividing the elements into two groups (function template)
stable_partition	divides elements into two groups while preserving their relative order (function template)
partition_point (C++11)	locates the partition point of a partitioned range (function template)
Sorting operations
Defined in header <algorithm>
is_sorted (C++11)	checks whether a range is sorted into ascending order (function template)
is_sorted_until (C++11)	finds the largest sorted subrange (function template)
sort	sorts a range into ascending order (function template)
partial_sort	sorts the first N elements of a range (function template)
partial_sort_copy	copies and partially sorts a range of elements (function template)
stable_sort	sorts a range of elements while preserving order between equal elements (function template)
nth_element	partially sorts the given range making sure that it is partitioned by the given element (function template)
Binary search operations (on sorted ranges)
Defined in header <algorithm>
lower_bound	returns an iterator to the first element not less than the given value (function template)
upper_bound	returns an iterator to the first element greater than a certain value (function template)
binary_search	determines if an element exists in a partially-ordered range (function template)
equal_range	returns range of elements matching a specific key (function template)
Other operations on sorted ranges
Defined in header <algorithm>
merge	merges two sorted ranges (function template)
inplace_merge	merges two ordered ranges in-place (function template)
Set operations (on sorted ranges)
Defined in header <algorithm>
includes	returns true if one sequence is a subsequence of another (function template)
set_difference	computes the difference between two sets (function template)
set_intersection	computes the intersection of two sets (function template)
set_symmetric_difference	computes the symmetric difference between two sets (function template)
set_union	computes the union of two sets (function template)
Heap operations
Defined in header <algorithm>
is_heap (C++11)	checks if the given range is a max heap (function template)
is_heap_until (C++11)	finds the largest subrange that is a max heap (function template)
make_heap	creates a max heap out of a range of elements (function template)
push_heap	adds an element to a max heap (function template)
pop_heap	removes the largest element from a max heap (function template)
sort_heap	turns a max heap into a range of elements sorted in ascending order (function template)
Minimum/maximum operations
Defined in header <algorithm>
max	returns the greater of the given values (function template)
max_element	returns the largest element in a range (function template)
min	returns the smaller of the given values (function template)
min_element	returns the smallest element in a range (function template)
minmax (C++11)	returns the smaller and larger of two elements (function template)
minmax_element (C++11)	returns the smallest and the largest elements in a range (function template)
clamp (C++17)	clamps a value between a pair of boundary values (function template)
Comparison operations
Defined in header <algorithm>
equal	determines if two sets of elements are the same (function template)
lexicographical_compare	returns true if one range is lexicographically less than another (function template)
lexicographical_compare_three_way (C++20)	compares two ranges using three-way comparison (function template)
Permutation operations
Defined in header <algorithm>
is_permutation (C++11)	determines if a sequence is a permutation of another sequence (function template)
next_permutation	generates the next greater lexicographic permutation of a range of elements (function template)
prev_permutation	generates the next smaller lexicographic permutation of a range of elements (function template)
Numeric operations
Defined in header <numeric>
iota (C++11)	fills a range with successive increments of the starting value (function template)
accumulate	sums up or folds a range of elements (function template)
inner_product	computes the inner product of two ranges of elements (function template)
adjacent_difference	computes the differences between adjacent elements in a range (function template)
partial_sum	computes the partial sum of a range of elements (function template)
reduce (C++17)	similar to std::accumulate, except out of order (function template)
exclusive_scan (C++17)	similar to std::partial_sum, excludes the ith input element from the ith sum (function template)
inclusive_scan (C++17)	similar to std::partial_sum, includes the ith input element in the ith sum (function template)
transform_reduce (C++17)	applies an invocable, then reduces out of order (function template)
transform_exclusive_scan (C++17)	applies an invocable, then calculates exclusive scan (function template)
transform_inclusive_scan (C++17)	applies an invocable, then calculates inclusive scan (function template)
Operations on uninitialized memory

Defined in header <memory>
uninitialized_copy	copies a range of objects to an uninitialized area of memory (function template)
uninitialized_copy_n (C++11)	copies a number of objects to an uninitialized area of memory (function template)
uninitialized_fill	copies an object to an uninitialized area of memory, defined by a range (function template)
uninitialized_fill_n	copies an object to an uninitialized area of memory, defined by a start and a count (function template)
uninitialized_move (C++17)	moves a range of objects to an uninitialized area of memory (function template)
uninitialized_move_n (C++17)	moves a number of objects to an uninitialized area of memory (function template)
uninitialized_default_construct (C++17)	constructs objects by default-initialization in an uninitialized area of memory, defined by a range (function template)
uninitialized_default_construct_n (C++17)	constructs objects by default-initialization in an uninitialized area of memory, defined by a start and a count (function template)
uninitialized_value_construct (C++17)	constructs objects by value-initialization in an uninitialized area of memory, defined by a range (function template)
uninitialized_value_construct_n (C++17)	constructs objects by value-initialization in an uninitialized area of memory, defined by a start and a count (function template)
destroy_at (C++17)	destroys an object at a given address (function template)
destroy (C++17)	destroys a range of objects (function template)
destroy_n (C++17)	destroys a number of objects in a range (function template)
C library
Defined in header <cstdlib>
qsort	sorts a range of elements with unspecified type (function)
bsearch	searches an array for an element of unspecified type (function)

See also

C documentation for Algorithms