70 lines
1.1 KiB
C++
70 lines
1.1 KiB
C++
#include <iostream>
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struct Node {
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Node* next;
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int message;
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};
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class Queue {
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private:
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Node* first = nullptr;
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Node* last = nullptr;
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size_t size = 0;
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public:
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void Add(int message) {
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Node* new_node = new Node {nullptr, message};
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if (size == 0) {
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first = new_node;
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} else {
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last->next = new_node;
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}
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++size;
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last = new_node;
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}
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int Pop() {
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if (size != 0) {
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Node* prev = first;
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int return_value = prev->message;
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first = prev->next;
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delete prev;
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--size;
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return return_value;
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}
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}
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};
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int main() {
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Queue queue;
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int n;
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int stack_idx = 0;
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std::cin >> n;
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int* return_values = new int[n];
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for (int i = 0; i < n; ++i) {
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char action;
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std::cin >> action;
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if (action == '+') {
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int message;
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std::cin >> message;
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queue.Add(message);
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} else {
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return_values[stack_idx] = queue.Pop();
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++stack_idx;
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}
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}
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for (int i = 0; i < stack_idx; ++i) {
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std::cout << return_values[i] << '\n';
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}
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delete[] return_values;
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return 0;
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}
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