백준 10866번 C++ 풀이

#include <iostream>

#include <cstring>

#include <algorithm>

#include <cmath>

#include <deque>

using namespace std;

char buffer[10000000];

int main() {

cin.tie(NULL);

ios::sync_with_stdio(false);

int n;

cin >> n;

deque<int> st;

for (int i = 0; i< n; i++) {

cin >> buffer;

if (strcmp(buffer, "push_front") == 0) {

int temp;

cin >> temp;

st.push_front(temp);

}

else if (strcmp(buffer, "push_back") == 0) {

int temp;

cin >> temp;

st.push_back(temp);

}

else if (strcmp(buffer, "front") == 0) {

if (st.empty()) {

cout << -1 << "\n";

}

else {

cout << st.front() << "\n";

}

}

else if (strcmp(buffer, "size") == 0) {

cout << st.size() << "\n";

}

else if (strcmp(buffer, "pop_front") == 0) {

if (st.empty()) {

cout << -1 << '\n';

}

else {

cout << st.front() << "\n";

st.pop_front();

}

}

else if (strcmp(buffer, "pop_back") == 0) {

if (st.empty()) {

cout << -1 << '\n';

}

else {

cout << st.back() << "\n";

st.pop_back();

}

}

else if (strcmp(buffer, "empty") == 0) {

if (st.empty()) {

cout << 1 << '\n';

}

else {

cout << 0 << '\n';

}

}

else if (strcmp(buffer, "back") == 0) {

if (st.empty()) {

cout << -1 << "\n";

}

else {

cout << st.back() << "\n";

}

}

}

return 0;

}