page_74_own_queue

#include <fstream>
using namespace std;
ifstream in ("input.txt");
ofstream out ("output.txt");

class Queue {
    struct Element {
        int inf;
        Element *next;
        Element(int x) : inf(x), next(0) {}
    };
    Element *head, *tail;
public:
    Queue() : head(0), tail(0) {}
    bool empty() { return head == 0;}
    int get() { if (empty()) return 0; else
        {
            Element *t = head;
            int i = t->inf;
            head = t->next;
            if (head == NULL) tail = NULL;
            delete t;
            return i;}}
    void pop() {
        //if (empty()) return 0;
        Element *t = head;
        head = head->next;
        if (head == NULL) tail = NULL;
        delete t;}
    int front() {
        return head->inf;}
    void push(int data){
        Element *t = tail;
        tail = new Element(data);
        if (!head) head = tail; else t->next = tail;}
};

int main (){
    Queue Q;
    int x, val;
    in >> x;
    while (in >> val)
        Q.push(val);
    in.close();
    while (!Q.empty()){
        if (Q.front() == x) { Q.pop(); continue;} else
            out << Q.front() << '\t';
        Q.pop();}
    out.close();
    return 0;
}