138 lines
3.1 KiB
C++
138 lines
3.1 KiB
C++
#include <stdio.h>
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template <class E> class Node {
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private:
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E content;
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Node<E> *next;
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public:
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Node(const E &_content) : content(_content), next(this){};
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Node(const E &_content, Node<E> *nextPtr)
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: content(_content), next(nextPtr){};
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void setNext(Node<E> *_ptr) {
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this->next = _ptr;
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}
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E &getContent() {
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return this->content;
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}
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Node<E> *getNextPtr() {
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return this->next;
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}
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};
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template <class E> class Iterator {
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private:
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Node<E> *current;
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public:
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Iterator(Node<E> *start) : current(start){};
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E &peekNext() {
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return this->current->getNextPtr()->getContent();
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}
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void next() {
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this->current = this->current->getNextPtr();
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}
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E &peek() {
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return this->current->getContent();
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}
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Node<E> *peekNode() {
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return this->current;
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}
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void insertHere(const E &newItem) {
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this->current->setNext(
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new Node<E>(newItem, this->current->getNextPtr()));
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}
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};
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template <class E> class List {
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private:
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// int _length;
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Node<E> head;
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public:
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List(const E &dummyValue)
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: head(Node<E>(dummyValue)){
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// this->_length = 0;
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};
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void insert(const E &target, const E &newItem) {
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Iterator<E> iter = Iterator<E>(&this->head);
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// Remember to add a loop to stop at length!!;
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while (iter.peek() != target) {
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iter.next();
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}
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iter.insertHere(newItem);
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// this->_length++;
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}
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void remove(const E &target) {
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Iterator<E> iter = Iterator<E>(&this->head);
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while (iter.peekNext() != target) {
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iter.next();
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}
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Node<E> *toBeDeleted = iter.peekNode()->getNextPtr();
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iter.peekNode()->setNext(toBeDeleted->getNextPtr());
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delete toBeDeleted;
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// this->_length--;
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}
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Iterator<E> iterate() {
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return Iterator<E>(&this->head);
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}
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};
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int read_num() {
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int summ = 0;
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char c = getchar();
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while (c < '0' || c > '9') {
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c = getchar();
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}
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while (c >= '0' && c <= '9') {
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summ = summ * 10 + c - '0';
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c = getchar();
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}
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return summ;
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}
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int main() {
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List<int> aList(0);
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aList.insert(0, 1);
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int n;
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int cmd, x, y;
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// scanf("%d", &n);
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n = read_num();
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while (n) {
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cmd = read_num();
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x = read_num();
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// scanf("%d %d", &cmd, &x);
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switch (cmd) {
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case 1: {
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// scanf("%d", &y);
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y = read_num();
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aList.insert(x, y);
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break;
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}
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case 2: {
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Iterator<int> iter = aList.iterate();
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while (iter.peek() != x) {
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iter.next();
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}
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printf("%d\n", iter.peekNext());
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break;
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}
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case 3: {
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aList.remove(x);
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}
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}
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n--;
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}
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Iterator<int> iter = aList.iterate();
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iter.next();
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while (true) {
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int content = iter.peek();
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if (content == 0) {
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break;
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}
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printf("%d\n", content);
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iter.next();
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}
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return 0;
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} |