Codeforce A. Yaroslav and Permutations

1. #include< iostream >
2. using namespace std;
3. int main() {
4. int n, x;
5. cin >> n;
6. int ar[10001] = {0};
7. for(int i = 0; i < n; i++) {
8. cin >> x;
9. ar[x]++;
10. if(ar[x] > (n+1)/2) return cout << "NO\n", 0;
11. }
12. cout << "YES\n";
13. return 0;
14. }

Codeforce A. Collecting Beats is Fun

1. #include< bits/stdc++.h >
2. using namespace std;
3. int main(){
4. int k;
5. char a;
6. cin >> k;
7. int ar[10] = {0};
8. for(int i = 0; i < 16; i++){
9. cin >> a;
10. ar[a]++;
11. }
12. for(int i = 1; i < 10; i++)
13. if(ar[i+'0'] > 2*k) return cout << "NO\n", 0;
14. cout << "YES\n";
15. return 0;
16. }

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;
	}

Queue implement by array in c++

	#include< iostream > using namespace std; int front = 0, rear = 0;
	void enqueue(int queue[], int element, int arrSize)
	{
	if(rear != arrSize){
	queue[rear] = element;
	rear++;
	}
	}
	void dequeue(int queue[])
	{
	if(front != rear){
	queue[front] = 0;
	front++;
	}
	}
	int frontData(int queue[])
	{
	return queue[front];
	}
	int size()
	{
	return rear - front;
	}
	bool isEmpty()
	{
	return front == rear;
	}
	int main()
	{
	int n, k;
	cin >> n;
	int queue[n+1];
	for(int i = 0; i < n; i++){
	cin >> k;
	enqueue(queue, k, n);
	}
	cout << "Queue size : " << size() << endl;
	cout << "Queue first element = " << frontData(queue) << endl;
	dequeue(queue);
	cout << "Queue new first element = " << frontData(queue) << endl;
	cout << "Queue is empty = " << (isEmpty()? "True":"False") << endl;
	cout << "Queue data are : " ;
	while(!isEmpty()) {
	cout << frontData(queue) << " ";
	dequeue(queue);
	}
	cout << endl;
	cout << "Queue is empty = " << (isEmpty()? "True":"False") << endl;
	return 0;
	}