[21.07.29]스택, 큐

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* 
* 
#include<iostream>
#include<queue>

using namespace std;
int de;

void BBQ(int* q) {
	*q = 10;
	return;
}

void ABC(int* p){
	BBQ(p);
	return;
	}


int main() {
	int ret;
	ABC(&ret);
	cout << ret;
	return 0;
}
* 
* ---------------큐
#include<iostream>
#include<queue>

using namespace std;

int main() {
	string str = "___AB_Q_R_T___C";
	queue<char> qu;

	int n = str.length();
	for (int i = 0; i < n; i++) {
		if (str[i] != '_')
		{
			qu.push(str[i]);
			str[i] = '_';
		}
	}
	int t = 0;
	while (!qu.empty()) {
		str[t] = qu.front();
		qu.pop();
		t++;
	}

	return 0;
}

* 
*
#include<iostream>
#include<queue>

using namespace std;

int main() {

	queue<int> qu;

	qu.push(3);
	qu.push(5);
	qu.push(10);
	qu.push(15);
	qu.push(20);

	int ret = qu.front(); //읽기
	qu.pop(); //제거
	ret = qu.front();
	qu.pop();

	qu.push(7);
	qu.push(11);

	while (!qu.empty()) {
		int ret = qu.front();
		qu.pop();

		cout << ret << " ";
	}
	return 0;
}

*
*------------------스택
#include<iostream>
#include<stack>

using namespace std;

int main() {
	int arr[] = { 3,2,1,5,7 };

	stack<int> st;

	for (int i = 0; i < 5; i++) {
		cout << arr[i] << " ";
		st.push(arr[i]);
	}

	while (!st.empty()) {
		int ret = st.top();
		st.pop();
		cout << ret << " ";
	}

	return 0;
}
* 
#include<iostream>
#include<stack>

using namespace std;

int main() {

	stack<int> bucket;
	bucket.push(3);
	bucket.push(2);
	bucket.push(1);
	bucket.push(7);
	bucket.push(5);

	int ret = bucket.top();
	bucket.pop();
	ret = bucket.top();
	bucket.pop();

	for (int i = 1; i <= 5; i++) {
		bucket.push(i);
	}

	while (!bucket.empty()) {
		int ret = bucket.top();
		bucket.pop();

		cout << ret << endl;
	}

	return 0;
}

* ------------------------------정올 큐
* #include<iostream>
#include<queue>

using namespace std;

int main() {
	int a, n;
	char order;
	queue<int> st;

	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> order;
		if (order == 'i') {
			cin >> a;
			st.push(a);
		}
		else if (order == 'o') {
			if (st.empty()) cout << "empty"<<endl;
			else {
				int ret = st.front();
				st.pop();
				cout << ret << endl;
			}
		}
		else if (order == 'c') {
			cout << st.size() << endl;
		}

	}

	return 0;
}
*------------------------------정올 스택
#include<iostream>
#include<stack>

using namespace std;

int main() {
	int a,n;
	char order;
	stack<int> st;

	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> order;
		if (order == 'i') {
			cin >> a;
			st.push(a);
		}else if (order == 'o') {
			if (st.empty()) cout << "empty"<<endl;
			else {
				int ret = st.top();
				st.pop();
				cout << ret << endl;
			}
		}
		else if (order == 'c') {
			cout << st.size() << endl;
		}

	}

	return 0;
}