113 lines
2.2 KiB
C++
113 lines
2.2 KiB
C++
/**~*~*~*
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CIS 22C
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Project: Queue of strings (pop)
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Written by: Iurii Tatishchev
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IDE: CLion
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*~*/
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#include <iostream>
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#include <string>
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using namespace std;
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class Queue_str {
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private:
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// Structure for the queue nodes
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struct QueueNode {
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string value; // Value in the node
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QueueNode *next; // Pointer to next node
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};
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QueueNode *front; // Pointer to the first node
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QueueNode *rear; // Pointer to the last node
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int length; // Number of nodes in the queue
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public:
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Queue_str() { front = rear = NULL; length = 0; } //Constructor
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~Queue_str(); // Destructor
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// Queue operations
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bool isEmpty() { return length == 0; }
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bool push(string);
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string pop();
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string peek() { return front->value; }
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string peekRear() { return rear->value; }
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int getLength() { return length; }
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};
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/**~*~*
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Member function push: inserts the argument into the queue
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*~**/
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bool Queue_str::push(string item) {
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QueueNode *newNode; // Pointer to a new node
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// Allocate a new node and store num there.
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newNode = new QueueNode;
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if (!newNode)
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return false;
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newNode->value = item;
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newNode->next = NULL;
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// Update links and counter
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if (!front) // front is NULL: empty queue
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front = newNode;
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else
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rear->next = newNode;
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rear = newNode;
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length++;
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return true;
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}
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/**~*~*~*
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Destructor
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*~**/
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Queue_str::~Queue_str() {
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while (front != nullptr) {
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QueueNode* nextNode = front->next;
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delete front;
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front = nextNode;
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}
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}
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/**~*~*~*
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Member function dequeue deletes the value at the front
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of the queue and returns it.
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Assume queue has at least one node
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*~**/
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string Queue_str::pop() {
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string item = front->value;
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QueueNode* oldFront = front;
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front = front->next;
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delete oldFront;
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length--;
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return item;
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}
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int main() {
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Queue_str que;
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string item;
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getline(cin, item);
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while (item != "#") {
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que.push(item);
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getline(cin, item);
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}
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if (que.isEmpty()) {
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cout << "Empty Queue!\n";
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return 0;
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}
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while (!que.isEmpty()) {
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cout << que.pop() << "\n";
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}
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return 0;
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} |