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Implementation of Vector
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| #include <iostream> | |
| #include <string> | |
| #include <exception> | |
| #include <stdexcept> | |
| #include <iterator> | |
| #include <algorithm> | |
| #include <memory> | |
| template <typename T> class Vector { | |
| std::unique_ptr<T[]> mem; | |
| T* pbegin; | |
| T* pend; | |
| T* tail; | |
| void resize(int new_size){ | |
| try{ | |
| std::unique_ptr<T[]> new_mem = std::unique_ptr<T[]>(new T[new_size]); | |
| auto new_pbegin = new_mem.get(); | |
| std::copy(pbegin,pend,new_pbegin); | |
| tail = new_pbegin + new_size; | |
| pend = new_pbegin + size(); | |
| std::swap(mem, new_mem); | |
| pbegin = new_pbegin; | |
| } | |
| catch(std::bad_alloc ex){ | |
| throw ex; | |
| } | |
| } | |
| public : | |
| Vector(int n){ | |
| if (n <= 0) | |
| throw std::invalid_argument("value can only be a natural number"); | |
| try{ | |
| mem = std::unique_ptr<T[]>(new T[n]); | |
| } | |
| catch (std::bad_alloc ex){ | |
| throw ex; | |
| } | |
| pbegin = mem.get(); | |
| pend = pbegin; | |
| tail = pbegin + n; | |
| } | |
| Vector():Vector(2){} | |
| ~Vector(){ | |
| } | |
| void push_back(T elm){ | |
| if (pend == tail){ | |
| expand(); | |
| } | |
| *pend = elm; | |
| pend ++; | |
| } | |
| void pop_back(){ | |
| pend--; | |
| if (pend < pbegin + (capacity() / 2)){ | |
| shrink_to_fit(); | |
| } | |
| } | |
| void insert(T elm, int n){ | |
| if(n < 0 || n >= size()) | |
| throw std::out_of_range("invalid index"); | |
| if(pend == tail) | |
| expand(); | |
| std::move(pbegin + n, pend, pbegin + n + 1); | |
| *(pbegin + n) = elm; | |
| pend ++; | |
| } | |
| int size(){ | |
| return pend - pbegin; | |
| } | |
| int capacity(){ | |
| return tail - pbegin; | |
| } | |
| bool empty(){ | |
| return pend == pbegin; | |
| } | |
| void expand(){ | |
| resize(capacity() * 2); | |
| std::cout << "EXPANDED" << std::endl; | |
| } | |
| void shrink_to_fit(){ | |
| resize(size()); | |
| std::cout << "SHRINKED" << std::endl; | |
| } | |
| T& operator[](int n){ | |
| if(n < 0 || n >= size()) | |
| throw std::out_of_range("Invalid Index"); | |
| return *(pbegin + n); | |
| } | |
| T* begin(){ | |
| return pbegin; | |
| } | |
| T* end(){ | |
| return pend; | |
| } | |
| T& front(){ | |
| this->operator[](0); | |
| } | |
| T& back(){ | |
| this->operator[](size() - 1); | |
| } | |
| }; | |
| int main(){ | |
| Vector<int> vec; | |
| for(int i = 0; i < 50; i++){ | |
| vec.push_back(i); | |
| } | |
| vec.insert(-1, 0); | |
| for(auto i : vec) | |
| std::cout << i << " "; | |
| std::cout << std::endl; | |
| auto itr = std::find(vec.begin(), vec.end(), 28); | |
| if(itr != vec.end()) | |
| std::cout << *itr << " found"; | |
| std::cout << " Front " << vec.front() << " " << " Back " << vec.back() <<std::endl; | |
| for(int i = 0; i < 49; i++){ | |
| vec.pop_back(); | |
| } | |
| std::cout << std::endl; | |
| for(auto i : vec) | |
| std::cout << i << " "; | |
| return 0; | |
| } |
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