[C/C ++ standard library] _ [Use of priority queue priority_queue]

Std: priority_queue

Scenario:

1. For a task queue, the priority of the task is specified by the priority attribute of the task. In this case, the task must be executed first with a higher priority. The queue does not have the sorting function. In this case, priority_queue is a good choice.

2. The same is true for asynchronous tasks. When new tasks are added continuously, execute tasks with a higher priority.

Resolution:

1. If you need to set the first pop with the highest priority, false must be returned for comp comparison.

Code:

//1.Elements are popped from the "back" of the specific container, //which is known as the top of the priority queue.//2.shall return true if a is considered to go before b // in the strict weak ordering the function defines#include 
 
  #include 
  
   #include 
   
    #include 
    
     using namespace std;class Task{public:Task(int priority):priority_(priority){}~Task(){}int priority_;void DoWork(){cout << "DoWork: " << (int)this << " priority: " << priority_ << endl;}};class PriorityCompare{public:bool operator()(Task* t1,Task* t2){return t1->priority_ > t2->priority_;}/* data */};int main(int argc, char const *argv[]){PriorityCompare pc;priority_queue
     
      ,PriorityCompare> tasks(pc);Task t1(1);Task t2(10);Task t3(3);Task t4(1);Task t5(8);Task t6(9);tasks.push(&t1);tasks.push(&t2);tasks.push(&t3);tasks.push(&t4);tasks.push(&t5);tasks.push(&t6);while(!tasks.empty()){Task* task = tasks.top();tasks.pop();task->DoWork();}return 0;}
     
    
   
  
 

Output:

DoWork: 2293456 priority: 1DoWork: 2293444 priority: 1DoWork: 2293448 priority: 3DoWork: 2293440 priority: 8DoWork: 2293436 priority: 9DoWork: 2293452 priority: 10

Reference: http://www.cplusplus.com/reference/queue/priority_queue/