queue

queue用法

• push(T e)
  入队操作

• pop()
  出队操作

• empty()
  判空，为空返回ture

• size()
  返回队列的大小

• front()
  队头元素

• back()
  队尾元素

• 不能使用迭代器遍历每个元素

测试

#include <iostream>  #include <queue>  using namespace std;void printQueue(queue<int>& q){    cout << endl << "--------- Queue Info --------" << endl;    cout << "[ " << q.back() << " --> " << q.front() << " ] ";    cout << " ( size : " << q.size() << " )" << endl;}int test(){    queue<int> myQueue;    cout << "初始化空队列, empty(): " << myQueue.empty() << endl;    int n;    cout << endl << "输入队列元素，也空格分开，Ctrl + Z 结束 ：" << endl;    while (cin >> n)myQueue.push(n);    printQueue(myQueue);    cout << endl << "Now, Let's pop() " << endl;    myQueue.pop();    cout << endl << "Let's push(15) " << endl;    myQueue.push(15);    printQueue(myQueue);    return 0;}

结果

初始化空队列, empty(): 1输入队列元素，也空格分开，Ctrl + Z 结束 ：21 123 421 123 21 13^Z--------- Queue Info --------[ 13 --> 21 ]  ( size : 6 )Now, Let's pop()Let's push(15)--------- Queue Info --------[ 15 --> 123 ]  ( size : 6 )请按任意键继续. . .

deque用法

deque是双向队列Double ended queue；can be accessed with random access iterator

deque是双端队列，是可以在两端扩展和收缩的连续容器。一般deque的实现是基于某种形式的动态数组，允许单个元素用随机获取

迭代器随机读取，数组容量自动管理。

因此它有和vector相似的函数，但在序列的开始也有高效的插入和删除。但不像vector，deque的元素并不是严格连续存储的。

vector和deque有相似的接口和相似的目的，但内部实现截然不同。

• push_front(T e)
  从队头入队操作

• pop_front()
  从队头出队操作

• push_back(T e)
  从队尾入队操作

• pop_back()
  从队尾出队操作

• empty()
  判空，为空返回ture

• size()
  返回队列的大小

• front()
  队头元素

• back()
  队尾元素

• 可以使用迭代器访问每个元素

for (myItor = d.begin(); myItor != d.end(); myItor++)    cout << *myItor << " ";

测试

#include <iostream>#include <deque>using namespace std;void showDeque(deque<int>& d){    deque<int>::iterator myItor;    cout << "[ ";    for (myItor = d.begin(); myItor != d.end(); myItor++)        cout << *myItor << " ";    cout << "]" << endl;}void push_front(deque<int>& d, int e){    d.push_front(e);    cout << "Now, push_front e = " << e <<", deque is :"<< endl;    showDeque(d);}void push_back(deque<int>& d, int e){    d.push_back(e);    cout << "Now, push_back e = " << e << ", deque is :" << endl;    showDeque(d);}void pop_front(deque<int>& d){    d.pop_front();    cout << "Now, pop_front, deque is :" << endl;    showDeque(d);}void pop_back(deque<int>& d){    d.pop_back();    cout << "Now, pop_back, deque is :" << endl;    showDeque(d);}int test(){    deque<int> myDeque;    push_front(myDeque, 1);    push_front(myDeque, 2);    push_back(myDeque,3);    push_back(myDeque, 4);    push_back(myDeque, 5);    push_front(myDeque, 6);    pop_back(myDeque);    pop_front(myDeque);    return 0;}

结果

Now, push_front e = 1, deque is :[ 1 ]Now, push_front e = 2, deque is :[ 2 1 ]Now, push_back e = 3, deque is :[ 2 1 3 ]Now, push_back e = 4, deque is :[ 2 1 3 4 ]Now, push_back e = 5, deque is :[ 2 1 3 4 5 ]Now, push_front e = 6, deque is :[ 6 2 1 3 4 5 ]Now, pop_back, deque is :[ 6 2 1 3 4 ]Now, pop_front, deque is :[ 2 1 3 4 ]请按任意键继续. . .

参考

c++ queue&dqueue