STL Iterators Algorithms
C++ Iterators
Iterators are used to access members of the container classes, and can be used in a similar manner to pointers. For example, one might use an iterator to step through the elements of a vector. There are several different types of iterators:
| Iterator | Description |
|---|---|
| input_iterator | Read values with forward movement. These can be incremented, compared, and dereferenced. |
| output_iterator | Write values with forward movement. These can be incremented and dereferenced. |
| forward_iterator | Read or write values with forward movement. These combine the functionality of input and output iterators with the ability to store the iterators value. |
| bidirectional_ite rator | Read and write values with forward and backward movement. These are like the forward iterators, but you can increment and decrement them. |
| random_iterator | Read and write values with random access. These are the most powerful iterators, combining the functionality of bidirectional iterators with the ability to do pointer arithmetic and pointer comparisons. |
| reverse_iterator | Either a random iterator or a bidirectional iterator that moves in reverse direction. |
C++ Algorithms
accumulate
sum up a range of elements
adjacent_difference
compute the differences between adjacent elements in a range
adjacent_find
finds two items that are adjacent to each other
binary_search
determine if an element exists in a certain range
copy
copy some range of elements to a new location
copy_backward
copy a range of elements in backwards order
copy_n
copy N elements
count
return the number of elements matching a given value
count_if
return the number of elements for which a predicate is true
equal
determine if two sets of elements are the same
equal_range
search for a range of elements that are all equal to a certain element
fill
assign a range of elements a certain value
fill_n
assign a value to some number of elements
find
find a value in a given range
find_end
find the last sequence of elements in a certain range
find_first_of
search for any one of a set of elements
find_if
find the first element for which a certain predicate is true
for_each
apply a function to a range of elements
generate
saves the result of a function in a range
generate_n
saves the result of N applications of a function
includes
returns true if one set is a subset of another
inner_product
compute the inner product of two ranges of elements
inplace_merge
merge two ordered ranges in-place
is_heap
returns true if a given range is a heap
is_sorted
returns true if a range is sorted in ascending order
iter_swap
swaps the elements pointed to by two iterators
lexicographical_compare
returns true if one range is lexicographically less than another
lexicographical_compare_3way
determines if one range is lexicographically less than or greater than another
lower_bound
search for the first place that a value can be inserted while preserving order
make_heap
creates a heap out of a range of elements
max
returns the larger of two elements
max_element
returns the largest element in a range
merge
merge two sorted ranges
min
returns the smaller of two elements
min_element
returns the smallest element in a range
mismatch
finds the first position where two ranges differ
next_permutation
generates the next greater lexicographic permutation of a range of elements
nth_element
put one element in its sorted location and make sure that no elements to its left are greater than any elements to its right
put
one element in its sorted location and make sure that no elements to its left are greater than any elements to its right
partial_sort
sort the first N elements of a range
partial_sort_copy
copy and partially sort a range of elements
partial_sum
compute the partial sum of a range of elements
partition
divide a range of elements into two groups
pop_heap
remove the largest element from a heap
prev_permutation
generates the next smaller lexicographic permutation of a range of elements
push_heap
add an element to a heap
random_sample
randomly copy elements from one range to another
random_sample_n
sample N random elements from a range
random_shuffle
randomly re-order elements in some range
remove
remove elements equal to certain value
remove_copy
copy a range of elements omitting those that match a certian value
remove_copy_if
create a copy of a range of elements, omitting any for which a predicate is true
remove_if
remove all elements for which a predicate is true
replace
replace every occurrence of some value in a range with another value
replace_copy
copy a range, replacing certain elements with new ones
replace_copy_if
copy a range of elements, replacing those for which a predicate is true
replace_if
change the values of elements for which a predicate is true
reverse
reverse elements in some range
reverse_copy
create a copy of a range that is reversed
rotate
move the elements in some range to the left by some amount
rotate_copy
copy and rotate a range of elements
search
search for a range of elements
search_n
search for N consecutive copies of an element in some range
set_difference
computes the difference between two sets
set_intersection
computes the intersection of two sets
set_symmetric_difference
computes the symmetric difference between two sets
set_union
computes the union of two sets
sort
sort a range into ascending order
sort_heap
turns a heap into a sorted range of elements
stable_partition
divide elements into two groups while preserving their relative order
stable_sort
sort a range of elements while preserving order between equal elements
swap
swap the values of two objects
swap_ranges
swaps two ranges of elements
transform
applies a function to a range of elements
unique
remove consecutive duplicate elements in a range
unique_copy
create a copy of some range of elements that contains no consecutive duplicates
upper_bound
searches for the last possible location to insert an element into an ordered range