15 standard library containers and iterators

本文主要是介绍15 standard library containers and iterators，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

demonstrating input and output with iterators
Standard library vector class template
testing standard library vector class template element-manipulation functions.
standard library list class template
standard library deque class template
Standard Library multiset class template
standard Library set class template
Standard Library multimap class template
Stardard Library class map class template
standard library stack adapter class
standard library queue adapter class template
Standard Library priority_queue adapter class

demonstrating input and output with iterators

#include <iostream>
#include <iterator>
using namespace std;int main() {cout << "Enter two integers:\n" ;istream_iterator<int> inputInt{cin}; // creatint number1{*inputInt};++inputInt;int number2{*inputInt};++inputInt;int number3{*inputInt};ostream_iterator<int> outputInt(cout);cout << "The sum is :";*outputInt = number1 + number2;++outputInt;cout << "\nthe number3 is :";*outputInt = number3;cout << endl;
}

2. Standard library vector class template

#include <iostream>
#include <vector>using namespace std;template<typename T>
void printVector(const vector<T> &integers) {for (auto const &item:integers) {cout << item << " ";}
}template <typename T>
void printVector2(const vector<T>& integers){
//    for(vector<int>::const_iterator constIterator = integers.cbegin(); constIterator != integers.cend(); ++constIterator) {for(vector<int>::const_iterator constIterator = integers.cbegin(); constIterator != integers.cend(); ++constIterator) {cout << *constIterator << " ";}
}int main() {vector<int> integres;cout << "The initial size of integers is :" << integres.size()<< "\nThe initial capacity of integers is :" << integres.capacity();integres.push_back(2);integres.push_back(3);integres.push_back(4);cout << "\n\nThe initial size of integers is :" << integres.size()<< "\nThe initial capacity of integers is :" << integres.capacity();cout << "\n\nprint vector items:";printVector(integres);cout << "\nprint reverse order:";for (auto reverseIterator = integres.crbegin(); reverseIterator != integres.crend(); ++reverseIterator) {cout << *reverseIterator << " ";}cout << "\nprint build_in array:";const size_t SIZE{6};int values[SIZE]{1, 2, 3, 4, 5, 6};for (const int *ptr = cbegin(values); ptr != cend(values); ++ptr) {cout << *ptr << " ";}
}

注意定义 iterators 的时候需要注意！

3. testing standard library vector class template element-manipulation functions.

// testing standard library vector class template element-manipulation functions.#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <stdexcept>using namespace std;int main() {vector<int> values{1, 2, 3, 4, 5, 6};vector<int> integers{values.cbegin(), values.cend()};ostream_iterator<int> output{cout, " "};cout << "Vector integers contain: ";copy(integers.cbegin(), integers.cend(), output);cout << "\nFirst element of integers: " << integers.front()<< "\nLast element of integers: " << integers.back();integers[0] = 7;integers.at(2) = 10;integers.insert(integers.cbegin() + 1, 22);cout << "\n\nContents of vector integers after changes: ";copy(integers.cbegin(), integers.cend(), output);try {integers.at(100) = 777;}catch (out_of_range &outOfRange) {cout << "\n\nException: " << outOfRange.what();}integers.erase(integers.cbegin()); // erase first elementcout << "\n\nVector integers after erasing first element: ";copy(integers.cbegin(), integers.cend(), output);integers.erase(integers.cbegin(), integers.cend());cout << "\nAfter earsing all elements, vector integers " << (integers.empty() ? "is ":"is not " ) << "empyt";integers.insert(integers.cbegin(), values.cbegin(), values.cend());
//    integers.insert(integers.cbegin(), 80);cout << "\n\nContents of vector integers before clear: ";copy(integers.cbegin(), integers.cend(), output);integers.clear();cout << "\nAfter clear, vector integers: " << (integers.empty() ? "is " :"is not " ) << "empty" << endl;
}

4. standard library list class template.


// standard library list class template.#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <iterator>using namespace std;template<typename T>
void printList(const list<T> &listRef);template<typename T>
void printList(const list<T> &listRef) {if (listRef.empty()) {cout << "List is empyt";} else {ostream_iterator<T> output{cout, " "};copy(listRef.cbegin(), listRef.cend(), output);}
}int main() {list<int> values;list<int> otherValues;values.push_front(1);values.push_front(2);values.push_back(4);values.push_back(3);cout << "values contains: ";printList(values);// sortvalues.sort(); // sort valuescout << "\nvalues after sorting contains: ";printList(values);// insert element of ints into otherValuesvector<int> ints{2, 6, 4, 8};otherValues.insert(otherValues.cbegin(), ints.cbegin(), ints.cend());cout << "\nAfter insert, otherValues contains: ";printList(otherValues);// remove otherValues elements and insert at end of valusevalues.splice(values.cend(), otherValues);cout << "\nAfter splice, values contains: ";printList(values);cout << "\nAfter splice, otherValues contains: ";printList(otherValues);// sortvalues.sort();cout << "\nAfter splice, sort, values contains: ";printList(values);// insert element into otherValuesotherValues.insert(otherValues.cbegin(), ints.cbegin(), ints.cend());otherValues.sort();cout << "\nAfter insert and sort, otherValues contains: ";printList(otherValues);// remove otherValues elements and insert into values in sorted order// merge 会抹去 otherValues 里面的内容values.merge(otherValues);cout << "\n\nAfter merge:\n values contains: ";printList(values);cout << "\n otherValues contains: ";printList(otherValues);values.pop_front();values.pop_back();cout << "\n\nAfter pop_front and pop_back:\n values contains: ";printList(values);// remove duplicate elementsvalues.unique();cout << "\nAfter unique, values contains: ";printList(values);cout << "\nnow otherValues contains: ";printList(otherValues);// swap element of values and otherValuesvalues.swap(otherValues);cout << "\n\nAfter swap:\n values contains: ";printList(values);cout << "\n otherValues contains: ";printList(otherValues);// replace contents of values with elements of otherValues, assign会保留自己values.assign(otherValues.cbegin(), otherValues.cend());cout << "\n\nAfter assign, values contains: ";printList(values);cout << "\nAfter assign, otherValues contains: ";printList(otherValues);// remove otherVales elements and insert into values in sorted ordervalues.merge(otherValues);cout << "\n\nAfter merge, values contains: ";printList(values);cout << "\nAfter merge, othervalues contains: ";printList(otherValues);values.remove(4); // remove all 4cout << "\n\nAfter remove(4), values contains: ";printList(values);cout << endl;}

5. standard library deque class template


// standard library deque class template#include <iostream>
#include <deque>
#include <algorithm>
#include <iterator>using namespace std;int main() {deque<double> values;ostream_iterator<double> output{cout, " "};// insert element in valuesvalues.push_front(2.2);values.push_front(3.5);values.push_back(1.1);cout << "values contains: ";copy(values.cbegin(), values.cend(), output);values.pop_front(); // remove first element// using  subscript operator to obtain element of valuescout << "\nAfter pop_front(), values contains: ";for (size_t i{0}; i < values.size(); ++i) {cout << values[i] << " ";}values[1] = 5.4;cout << "\nAfter values[1]=5.4, values contains: ";copy(values.cbegin(), values.cend(), output);cout << endl;}

6. Standard Library multiset class template

// Standard Library multiset class template#include <array>
#include <iostream>
#include <set>
#include <algorithm>
#include <iterator>
#include <vector>using namespace std;int main() {multiset<int, less<int>> intMultiset;cout << "There are currently " << intMultiset.count(15)<< " values of 15 in the multiset\n";intMultiset.insert(15);intMultiset.insert(15);cout << "After inserts, there are " << intMultiset.count(15)<< " values of 15 in themultiset\n\n";auto result{intMultiset.find(15)};if (result != intMultiset.end()) {cout << "Found value 15\n";}result = intMultiset.find(20);if (result == intMultiset.end()) {cout << "Did not find value 20\n";}vector<int> a{7, 22, 9, 1, 18, 30, 100, 22, 85, 13};intMultiset.insert(a.cbegin(), a.cend());cout << "\nAfter insert, intMultiset contains:\n";ostream_iterator<int> output{cout, " "};copy(intMultiset.begin(), intMultiset.end(), output);cout << "\n\nLower bound of 22: " << *(intMultiset.lower_bound(22));cout << "\nUpper bound of 22: " << *(intMultiset.upper_bound(22));auto p{intMultiset.equal_range(22)};cout << "\n\nequal_range of 22: " << "\n Lower bound: " << *(p.first)<< "\n Upper bound: " << *(p.second);cout << endl;
}

7. standard Library set class template

// standard Library set class template.
#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <iterator>
using namespace std;int main() {vector<double> a {2.1, 4.2, 9.5, 2.1, 3.7};set<double, less<double>> doubleSet{a.begin(), a.end()};cout << "double contains: ";ostream_iterator<double> output{cout, " "};copy(doubleSet.begin(), doubleSet.end(), output);auto p{doubleSet.insert(13.8)};cout << "\n\n" << *(p.first) << (p.second ? " was " : " was not ") << "insertd";cout << "\ndoubleSet contains: ";copy(doubleSet.begin(), doubleSet.end(), output);auto p2{doubleSet.insert(9.5)};cout << "\n\n" << *(p2.first) << (p2.second ? " was " : " was not ") << "insertd";cout << "\ndoubleSet contains: ";copy(doubleSet.begin(), doubleSet.end(), output);}

8.Standard Library multimap class template

// Standard Library multimap class template#include <iostream>
#include <map>
using namespace std;int main() {multimap<int, double, less<int>> pairs;cout << "There are currently " << pairs.count(15)<< " pairs with key 15 in the multimap\n";//    pairs.insert(make_pair(15, 99.3));pairs.insert({15, 99.3}); // 另一种写法pairs.insert(make_pair(15, 2.7));cout << "There are currently " << pairs.count(15)<< " pairs with key 15 in the multimap\n";pairs.insert(make_pair(30, 111.11));pairs.insert(make_pair(10, 22.22));pairs.insert(make_pair(25, 33.333));pairs.insert(make_pair(20, 9.345));pairs.insert(make_pair(5, 77.54));cout << "\nMultimap pairs contains:\nKey\tValue\n";for (auto mapItem:pairs) {cout << mapItem.first << "\t" << mapItem.second << "\n";}cout << endl;
}

9.Stardard Library class map class template

// Stardard Library class map class template#include <iostream>
#include <map>
using namespace  std;int main() {map<int, double, less<int>> pairs;pairs.insert({15, 2.7});pairs.insert(make_pair(30, 111.11));pairs.insert(make_pair(5, 1010.1));pairs.insert(make_pair(10, 22.22));pairs.insert(make_pair(25, 33.333));pairs.insert(make_pair(5, 77.54)); // dup ignoredpairs.insert(make_pair(20, 9.345));pairs.insert(make_pair(15, 99.3)); // dup ignoredcout << "\n\npairs contains:\nKey\tValue\n";for (auto mapItem:pairs) {cout << mapItem.first << "\t" << mapItem.second << "\n";}pairs[25] = 999.99;pairs[40] = 8765.43;cout << "\n\npairs contains:\nKey\tValue\n";for (auto mapItem:pairs) {cout << mapItem.first << "\t" << mapItem.second << "\n";}cout << endl;
}

10.standard library stack adapter class

// standard library stack adapter class
#include <iostream>
#include <stack>
#include <vector>
#include <list>using namespace std;template<typename T>
void pushElement(T &stackRef);template<typename T>
void popElement(T &stackRef);int main() {stack<int> intDequeStack;stack<int, vector<int>> intVectorStack;stack<int, list<int>> intListStack;cout << "Pushing onto intDequeStack: ";pushElement(intDequeStack);cout << "\nPushing onto intVectorStack: ";pushElement(intVectorStack);cout << "\nPushing onto intListStack: ";pushElement(intListStack);cout << "\n\nPopping from intDequeStack: ";popElement(intDequeStack);cout << "\nPushing onto intVectorStack: ";popElement(intVectorStack);cout << "\nPushing onto intListStack: ";popElement(intListStack);
}template<typename T>
void pushElement(T &stackRef) {for (int i{0}; i < 10; ++i) {stackRef.push(i);cout << stackRef.top() << " "; // view and display top element}
}template<typename T>
void popElement(T &stackRef) {while (!stackRef.empty()) {cout << stackRef.top() << " "; // top 不会删除元素stackRef.pop();}
}

11. standard library queue adapter class template

// standard library queue adapter class template#include <iostream>
#include <queue>
using namespace std;int main() {queue<double>  values;values.push(3.2);values.push(9.8);values.push(5.4);cout << "Popping from values: ";while (!values.empty()) {cout << values.front() << " ";values.pop();}cout << endl;
}

12. Standard Library priority_queue adapter class

// Standard Library priority_queue adapter class
// heap 的意思，小顶堆、大顶堆 ， by default less<T>
#include <iostream>
#include <queue>using namespace std;int main() {priority_queue<double> priorities;priorities.push(3.2);priorities.push(9.8);priorities.push(5.4);cout << "Popping from priorities: ";while (!priorities.empty()) {cout << priorities.top() << " ";priorities.pop();}cout << endl;
}