Programming, Data Structures & Algorithms

Queue:  A queue is a container that implements the first in first out protocol. That means that the only accessible object in the container is the one among them that was inserted first. A good analogy is a group of people waiting in line of a ticket. The next one admitted is the person in the line who got here ahead of everyone else.   Common operations of queue on C++ are bool empty() Returns True if the queue is empty, and False otherwise. T & front() Returns a reference to the value at the front of a non-empty queue. There is also a constant version of this function,  const T & front() . void pop() Removes the item at the front of a non-empty queue. void push(const T &foo) Inserts the argument foo at the back of the queue. size_type size() Returns the total number of elements in the queue. Example: Stuck Implementation on C++  #include<iostream> #include<queue> using namespace std; template <class T> void print (const queue <T> &);

Stuck: Stack is a last in, first out (LIFO) abstract data type and data structure. It is a container that implements the last in first out (LIFO) Protocol. That means that the only accessible object in the container is the last one among them that was inserted. A stack of book is a good analogy: you can’t read any in the stack without first removing the books that are stacked on top of it. It has three fundamental operations: push, pop and stack top. When we using stack, we need a header file called stack. Example: Stuck Implementation on C++ #include<stack> using namespace std; int main(){ stack<string> s; s.push("Linux"); s.push("JAVA"); s.push("Oracle"); s.push("PHP"); cout<< "s.size() = " << s.size() << "\n"; while(!s.empty()){ cout << "s.top() = " <<s.top() <<"\n";    s.pop(); } cout<< "s.size() = " << s.s