Overview Containers and Class Vector
Container Types Sequence Containers Associative Containers Adapter Classes The List Container Stack Containers Queue Containers Priority Queue Containers Set Containers Map Containers C++ Arrays Vectors Insertion Sort Template Class Store Class
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STL C++ STL provides 10 container classes 4 additional types considered "near-containers"
array string bitset valarray
Extensions
to Standard
slist rope huge strings hash_set, hash_map, hash_multiset, hash_multimap
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Container Types Sequence Containers Vector Deque List Adapter Containers Stack Queue Priority Queue Associative Containers Set, Multiset Map, Multimap
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Sequence Containers A sequence container stores data by position in linear order 1st element, 2nd element, and so forth
S e q u e n c e C o n t a in e r
P o s it io n 0
P o s it io n 1
P o s it io n 2
P o s it io n 3
P o s it io n 4
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Associative Containers Associative containers store elements by key
Ex: name, SS #, or part number
A
program accesses an element in an associative container by its key
May bear no relationship to the location of the element in the container Access by key O(lg N)
Implementation?
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Adapter Classes Use a sequence container as underlying storage structure
E.g. Stack and Queue use Deque Design Pattern: Adapter
Adapter's
interface provides a restricted set of operations from underlying storage structure
How is stack restricted? queue?
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The List Container
n ext n ext n ext n ext
fro n t
rear
B e fo re 3 fro nt
7
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Inserting into a List Container
6 4 3 fro nt
12
A fte r //
15
6
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Stack Containers A stack allows access at only one end of sequence, called the top.
C
A C B A
top
B A
top Push C
B A
top
top
A
B
top
Push A
Push B (a)
Pop C
Pop B (b)
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Queue Containers A queue is a container that allows access only at front and back
A
B
C
D Insert E back A front
B
C
D
E
Delete
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Priority Queue Containers priority queue -- HPFO Push elements in any order -- pop operation removes the largest (or smallest) value
V a lu e = 8 18 3 27 15 13
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Set Containers A set is a collection of unique values, called keys or set members.
S et A 5 3 27 15 1
S et B B u ic k F o rd H onda BM W Jagu ar Jeep
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Map Containers A map is a storage structure that implements a keyvalue relationship.
In d ex A 2 9 -4 6 8 D 7 B -9 1 6 W 9 1 -A 8 3 P art# D 7 B -9 1 6 W 9 1 -A 8 3 A 2 9 -4 6 8 P r ic e 4 .9 5 1 2 .5 0 8 .7 5 V endor M ir a g e C a llo w a y M a r t in
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C++ Arrays Fixed-size collection homogenous Stores the n (size) elements in contiguous block
arr[0 ] 0
arr[1 ] 1
arr[2 ] 2
...
arr[n -1 ] n -1
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Evaluating an Array as a Container Size is fixed at the time of its declaration
Does an array know its size?
C++
arrays do not allow the assignment of one array to another
Requires loop structure with the array size as an upper bound *or* what algorithm?
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Vectors
v [0 ] 0
v [1 ] 1
v[2] 2
. . .
v [n -1 ] n -1
ro o m to g ro w
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CLASS vector
Constructors
<vector>
vector(); Create an empty vector. This is the default constructor. vector(int n, const T& value = T()); Create a vector with n elements, each having a specified value. If the value argument is omitted, the elements are filled with the default value for type T. Type T must have a default constructor, and the default value of type T is specified by the notation T().
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CLASS vector
Constructors
<vector>
vector(InputIter first, InputIter last); Initialize the vector using the range [first, last). first and last are input iterators (can be read).
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CLASS vector
Operations
<vector>
T& back(); Return the value of the item at the rear of the vector. Precondition: The vector must contain at least one element. const T& back() const; Constant version of back(). bool empty() const; Return true if the vector is empty and false otherwise.
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CLASS vector
Operations
<vector>
T& operator[] (int i); Allow the vector element at index i to be retrieved or modified. Precondition: The index, i, must be in the range 0 i < n, where n is the number of elements in the vector. Postcondition: If the operator appears on the left side of an assignment statement, the expression on the right side modifies the element referenced by the index. const T& operator[] (int i) const; Constant version of the index operator.
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CLASS vector
Operations
<vector>
void push_back(const T& value); Add a value at the rear of the vector. Postcondition: The vector has a new at element the rear and its size increases by 1. void pop_back(); Remove the item at the rear of the vector. Precondition: The vector is not empty. Postcondition: The vector has a new element at the rear or is empty.
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CLASS vector
Operations
<vector>
iterator erase(iterator pos); Erase the element pointed to by pos. Precondition: The vector is not empty. Postcondition: The vector has one fewer element. iterator erase(iterator first, iterator last); Erase all elements within the iterator range [first, last). Precondition: The vector is not empty. Postcondition: The size decreases by the number of elements in the range. Both invalidate iterators beyond range erased.
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CLASS vector
Operations
<vector>
iterator insert(iterator pos, const T& value); Insert value before pos, and return an iterator pointing to the position of the new value in the vector. The operation invalidates any existing iterators beyond pos. Postcondition: The list has a new element.
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CLASS vector
Operations
<vector>
void resize(int n, const T& fill = T()); Modify the size of the vector. If the size is increased, the value fill is added to the elements on the tail of the vector. If the size is decreased, the original values at the front are retained. Postcondition: The vector has size n. void reserve (size_type n); Only will increase capacity. Postcondition: capacity () >= n size_t size() const; Return the number of elements in the vector.
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Output with Vectors template <typename T> void writeVector(const vector<T>& v) {
// capture the size of the vector in n
size_t i, n = v.size (); for (i = 0; i < n; ++i) cout << v[i] << " "; cout << endl; } *or*
copy (...); // ??
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Declaring Vector Objects
// vector of size 5 containing the integer // value 2
vector<int> intVector(5, 2);
// vector of size 10; each element // contains the empty string
vector<string> strVector(10);
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Adding and Removing Vector Elements
v.size == 4 () 12 0 -5 1 8 2 14 3 12 0 v.size == 5 () -5 1 8 2 14 3 10 4
Before
After v.push_back(10)
v.size() == 2 4.6 0 6.8 1
v.size() == 1 4.6 0 After v.pop _back()
Before
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Resizing a Vector int arr[5] = {7, 4, 9, 3, 1}; vector<int> v(arr,arr+5);
integers // v initially has 5
v.resize(10);// list size is doubled v.resize(4); // list is contracted; data
// is lost
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Resizing a Vector (cont'd)
vector<int> v(arr,arr + 5) 7 4 9 3 1
v.resize (10); 7 4 9 3 1 0 0 0 0
v.resize (4); 7 4 9 3
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Insertion Sort Can use with vector's or arrays Best-case run time? Worst-case?
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The Insertion Sort
M o n ro e
S tar t w ith M o n r o e In s e r t C h in in lo c a tio n 0 ; M o n r o e m o ve s to lo c atio n 1
P ro c...