71 lines
1.2 KiB
C++
71 lines
1.2 KiB
C++
#include <iostream>
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#include <vector>
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using namespace std;
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class AbstractIterator
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{
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public:
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virtual void *next() = 0;
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};
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class PageIterator : public AbstractIterator
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{
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protected:
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vector<void *> v;
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int pos = 0;
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public:
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PageIterator(vector<void *> v)
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{
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this->v = v;
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}
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void *next()
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{
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if (pos >= v.size())
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{
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return NULL;
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}
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return v[pos++];
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}
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};
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class List
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{
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protected:
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vector<void *> v;
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public:
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void add(void *data)
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{
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v.insert(v.end(), data);
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}
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AbstractIterator *page(int page)
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{
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vector<void *> p(v.begin() + ((page - 1) * 5), v.begin() + (page * 5));
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return new PageIterator(p);
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}
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};
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int main()
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{
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List *list = new List();
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for (int i = 0; i < 8; i++)
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{
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int *tmp = (int *)malloc(sizeof(int));
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*tmp = i;
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list->add(tmp);
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}
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AbstractIterator *iterator = list->page(1);
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void *next;
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cout << "page1:\n";
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while ((next = iterator->next()) != NULL)
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{
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cout << *(int *)next << "\t";
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}
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cout << "\npage2:\n";
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iterator = list->page(2);
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while ((next = iterator->next()) != NULL)
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{
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cout << *(int *)next << "\t";
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}
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return 0;
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} |