1069 - Diamonds and Sand

#include< bits/stdc++.h >
using namespace std;

int main()
{
    int n;
    string s;
    cin  >>  n;

    while(n--) {
        stack< char >st;
        int ans = 0;
        cin  >>  s;
        for(auto ch: s) {
            if(ch == '<') st.push(ch);
            else if( !st.empty() and ch == '>' ) {
                ans++;
                st.pop();
            }
        }
        cout << ans << endl;
    }

    return 0;
}

Implement queue using two stack in cpp

	#include< iostream > #include< stack >
	using namespace std;
	stack<int> s1, s2;
	void enqueue(int data)
	{
	while(!s1.empty()) {
	s2.push(s1.top());
	s1.pop();
	}
	s1.push(data);
	while(!s2.empty()) {
	s1.push(s2.top());
	s2.pop();
	}
	}
	void dequeue()
	{
	if(!s1.empty()) {
	s1.pop();
	}
	}
	int front()
	{
	return s1.top();
	}
	bool isEmpty()
	{
	return s1.size() == 0;
	}
	int size()
	{
	return s1.size();
	}
	void printData()
	{
	while(!s1.empty()) {
	cout << s1.top() << " ";
	s1.pop();
	}
	cout << endl;
	}
	int main()
	{
	int n, m, k;
	cin >> n;
	for(int i = 0; i < n; i++) {
	cin >> k;
	enqueue(k);
	}
	cout << "Queue is empty : " << (isEmpty()?"True":"False") << endl;
	cout << "Queue front element : " << front() << endl;
	dequeue();
	cout << "Queue size : " << size() << endl;
	enqueue(12);
	enqueue(6);
	cout << "Queue new size : " << size() << endl;
	cout << "Queue new element are : ";
	printData();
	cout << "Queue is empty : " << (isEmpty()?"True":"False") << endl;
	return 0;
	}