C++/Queue Stack/queue

Материал из C\C++ эксперт
Перейти к: навигация, поиск

Put string into a queue

  
#include <iostream>
#include <string>
#include <queue>
#include <stack>
using namespace std;
int main()
{
   cout << "FIFO order:\n";
   queue<string> q;
   q.push("A");
   q.push("B");
   q.push("C");
   stack<string> s;
   while (q.size() > 0)
   {
      string name = q.front();
      q.pop();
      cout << name << "\n";
      s.push(name);
   }
   cout << "LIFO order:\n";
   while (s.size() > 0)
   {
      cout << s.top() << "\n";
      s.pop();
   }
   return 0;
}


queue.front()

   
 
#include <iostream>
using std::cout;
using std::endl;
#include <queue>
int main()
{
   std::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;
   return 0;
}
 /* 
Popping from values: 3.2 9.8 5.4
 */


Queue of string: push(), empty(), front(), pop()

   
#include <iostream>
#include <string>
#include <queue>
using namespace std;
int main()
{
    queue<string> q;
    q.push( "A" );
    q.push( "B" );
    q.push( "C" );
    while ( !q.empty() ) {
        cout << q.front() << " ";
        q.pop();
     }
     return 0;
}


Queue: push, pop and size

   
 

#include <iostream>
#include <queue> 
#include <list>
using namespace std;
int main()
{
  int thedata[] = {45, 34, 56, 27, 71, 50, 62};
  queue<int, list<int> > q;  
  cout << "The queue size is now " << q.size() << endl;
  cout << "Pushing 4 elements " << endl;
  for (int i = 0; i < 4; ++i)
    q.push(thedata[i]);
  cout << "The queue size is now " << q.size() << endl;
  cout << "Popping 3 elements " << endl;
  for (int i = 0; i < 3; ++i) {
    cout << q.front() << endl;
    q.pop();
  }
  cout << "The queue size is now " << q.size() << endl;
  return 0;
}
 /* 
The queue size is now 0
Pushing 4 elements
The queue size is now 4
Popping 3 elements
45
34
56
The queue size is now 1
 */


queue: push, pop, front and size

   
 
/* The following code example is taken from the book
 * "The C++ Standard Library - A Tutorial and Reference"
 * by Nicolai M. Josuttis, Addison-Wesley, 1999
 *
 * (C) Copyright Nicolai M. Josuttis 1999.
 * Permission to copy, use, modify, sell and distribute this software
 * is granted provided this copyright notice appears in all copies.
 * This software is provided "as is" without express or implied
 * warranty, and with no claim as to its suitability for any purpose.
 */
#include <iostream>
#include <queue>
#include <string>
using namespace std;
int main()
{
    queue<string> q;
    // insert three elements into the queue
    q.push("These ");
    q.push("are ");
    q.push("more than ");
    // read and print two elements from the queue
    cout << q.front();
    q.pop();
    cout << q.front();
    q.pop();
    // insert two new elements
    q.push("four ");
    q.push("words!");
    // skip one element
    q.pop();
    // read and print two elements
    cout << q.front();
    q.pop();
    cout << q.front() << endl;
    q.pop();
    // print number of elements in the queue
    cout << "number of elements in the queue: " << q.size()
         << endl;
}
 /* 
These are four words!
number of elements in the queue: 0
 */


queue with doubles

   
 
#include <iostream>
using std::cout;
using std::endl;
#include <queue>
int main()
{
   std::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;
   return 0;
}
/* 
Popping from values: 3.2 9.8 5.4
 */