std::queue is a container adaptor that gives the programmer the functionality of a queue - specifically, a FIFO (first-in, first-out) data structure.

Essential for Breadth-First Search (BFS), job scheduling, and handling requests in a sequential manner.

• Push: $O(1)$
• Pop: $O(1)$
• Front: $O(1)$

cpp Standard
#include <queue>

std::queue<int> q;
q.push(10);
q.push(20);

std::cout << q.front(); // 10
q.pop();
std::cout << q.front(); // 20

• Empty Queue Pop: Trying to pop() or access front() on an empty queue (always check q.empty() first).
• Thinking it's a priority queue (which sorts elements).
• Trying to access elements at the back or middle (use std::deque or std::vector for that).