583 Digit Generator in cpp solution

	#include< bits/stdc++.h > using namespace std;
	int main()
	{
	ios::sync_with_stdio(false);cin.tie(0);
	int n, k;
	cin >> n;
	while(n--) {
	cin >> k;
	int ans = 0, res = 0;
	int range = (k < 10) ? 9 : (k < 100)? 18: (k < 1000)? 27: (k < 10000)? 45 : 60;
	for(int i = k - range; i <= k; i++) {
	int num = i, sum = i;
	while( num != 0) {
	sum += num%10;
	num /= 10;
	}
	if(sum == k) {
	ans = 1;
	res = i;
	break;
	}
	}
	cout << ((ans)? res : 0 ) << endl;
	}
	return 0;
	}

Double ended queue in cpp

	#include< iostream > using namespace std;
	int queue[1001], front = 0, rear = 0;
	void enqueueBack(int element, int n)
	{
	if(rear != n) {
	queue[rear] = element;
	rear++;
	}
	}
	void enqueueFront(int element, int n)
	{
	if(rear != n) {
	for(int i = rear; i > front; i--) {
	queue[i] = queue[i-1];
	}
	queue[front] = element;
	rear++;
	}
	}
	void dequeueBack()
	{
	if(front != rear) {
	queue[--rear] = 0;
	}
	}
	void dequeueFront()
	{
	if(front != rear){
	queue[front++] = 0;
	}
	}
	int get_front()
	{
	return queue[front];
	}
	int get_back()
	{
	return queue[rear-1];
	}
	int size()
	{
	return rear - front;
	}
	bool isEmpty()
	{
	return front == rear;
	}
	int main()
	{
	int n, k, m;
	cin >> n >> m;
	for(int i = 0; i < n; i++) {
	cin >> k;
	enqueueFront(k, n);
	}
	cout << "Queue element are :";
	for(int i = 0; i < n; i++) cout << queue[i] << " ";
	cout << endl;
	for(int i = 0; i < m; i++) {
	cin >> k;
	enqueueBack(k,n+m);
	}
	cout << "Queue element are :";
	for(int i = 0; i < n+m ; i++) cout << queue[i] << " ";
	cout << endl;
	cout <<"Queue size :" << size() << endl;
	cout << "Queue is empty = " << (isEmpty()? "True":"False") << endl;
	cout << "Queue front element = " << get_front() << endl;
	cout << "Queue back element = " << get_back() << endl;
	dequeueFront();
	dequeueBack();
	cout << "Queue new front element = " << get_front() << endl;
	cout << "Queue new back element = " << get_back() << endl;
	cout <<"Queue new size :" << size() << endl;
	return 0;
	}