int main(){
std::vector<int>v{1,2,3,4};
std::vector<int>::iterator it = std::find(v.begin(), v.end(), 2);
if(it != v.end())
{
v.erase(it);
it++;//調(diào)用erase()后，it已經(jīng)失效了，運(yùn)行后迭代器引發(fā)異常
}
return 0;
}

int main(
std::vector<int> v{1,2,3,4};
std::vector<int>::iterator it = std: :find(v.begin(), v. end(),2);
if(it != v.end())
{
it=v.erase(it);//讓當(dāng)前迭代器接收erase的返回值，更新迭代器
it++;
}
return 0;
}

vector(size_t n, const T& val = T())//這里的形參用size_t就會(huì)引發(fā)這兩個(gè)構(gòu)造函數(shù)調(diào)用問(wèn)題
    :_start(nullptr)
    , _finish(nullptr)
    , _end_of_storage(nullptr)
{
    reserve(n);
    for (size_t i = 0; i < n; ++i)
    {
        push_back(val);
    }
}
 
template <class InputIterator>
vector(InputIterator first, InputIterator last)
    :_start(nullptr)
    , _finish(nullptr)
    , _end_of_storage(nullptr)
{
    while (first != last)
    {
        push_back(*first++);
    }
}

void reserve(size_t n)
{
    //擴(kuò)容
    if (n > capacity())
    {
        size_t oldSize = size();//先記錄下size,后續(xù)解決finish失效
        T* tmp = new T[n];
        if (_start != nullptr)
        {
            //memcpy(tmp, _start, sizeof(T) * oldSize);//淺拷貝
            for (size_t i = 0; i < oldSize; ++i)
            {
                tmp[i] = _start[i];//調(diào)用賦值運(yùn)算符重載完成深拷貝
            }
            delete[] _start;
        }
        _start = tmp;
        _finish = _start + oldSize;//異地?cái)U(kuò)容后_finish失效，需重新設(shè)定_finish
        _end_of_storage = _start + n;
    }
}

#pragma once
#include <iostream>
#include <assert.h>
using std::cout;
using std::cin;
using std::endl;
namespace jly
{
	template <class T>
	class vector
	{
	public:
		//構(gòu)造函數(shù)
		vector()
			:_start(nullptr)
			, _finish(nullptr)
			, _end_of_storage(nullptr)
		{}
		vector(size_t n, const T& val = T())
			:_start(nullptr)
			, _finish(nullptr)
			, _end_of_storage(nullptr)
		{
			reserve(n);
			for (size_t i = 0; i < n; ++i)
			{
				push_back(val);
			}
		}
		vector(int n, const T& val = T())//多重載一個(gè)int版本的構(gòu)造，解決調(diào)函數(shù)不明確的問(wèn)題
			:_start(nullptr)
			, _finish(nullptr)
			, _end_of_storage(nullptr)
		{
			reserve(n);
			for (int i = 0; i < n; ++i)
			{
				push_back(val);
			}
		}
 
		template <class InputIterator>
		vector(InputIterator first, InputIterator last)
			:_start(nullptr)
			, _finish(nullptr)
			, _end_of_storage(nullptr)
		{
			while (first != last)
			{
				push_back(*first++);
			}
		}
		//拷貝構(gòu)造
		void swap(vector<T>& v)//一定要加引用，不然拷貝構(gòu)造函數(shù)調(diào)用swap會(huì)引發(fā)無(wú)限拷貝
		{
			std::swap(_start, v._start);
			std::swap(_finish, v._finish);
			std::swap(_end_of_storage, v._end_of_storage);
		}
		vector(const vector<T>& v)
			: _start(nullptr)
			, _finish(nullptr)
			, _end_of_storage(nullptr)
		{
			vector<T> tmp(v.begin(), v.end());
			swap(tmp);
		}
		//vector(const vector<T>& v)//寫法二
		//	: _start(nullptr)
		//	, _finish(nullptr)
		//	, _end_of_storage(nullptr)
		//{
		//	reserve(v.capacity());
		//	for (const auto& e : v)
		//	{
		//		push_back(e);
		//	}
		//}
		//賦值運(yùn)算符重載
		vector<T>& operator=(vector<T> v)//能解決自己給自己賦值的問(wèn)題
		{
			swap(v);
			return *this;
		}
		//析構(gòu)函數(shù)
		~vector()
		{
			delete[] _start;
			_start = _finish = _end_of_storage = nullptr;
		}
		//迭代器
		typedef T* iterator;
		iterator begin()
		{
			return _start;
		}
		iterator end()
		{
			return _finish;
		}
		const iterator begin()const
		{
			return _start;
		}
		const iterator end()const
		{
			return _finish;
		}
		T& operator[](size_t pos)
		{
			return _start[pos];
		}
		const T& operator[](size_t pos)const
		{
			return _start[pos];
		}
		//reserve接口
		void reserve(size_t n)
		{
			//擴(kuò)容
			if (n > capacity())
			{
				size_t oldSize = size();//先記錄下size,后續(xù)解決finish失效
				T* tmp = new T[n];
				if (_start != nullptr)
				{
					//memcpy(tmp, _start, sizeof(T) * oldSize);//淺拷貝
					for (size_t i = 0; i < oldSize; ++i)
					{
						tmp[i] = _start[i];//調(diào)用賦值運(yùn)算符重載完成深拷貝
					}
					delete[] _start;
				}
				_start = tmp;
				_finish = _start + oldSize;//異地?cái)U(kuò)容后_finish失效，需重新設(shè)定_finish
				_end_of_storage = _start + n;
			}
		}
		//resize接口
		void resize(size_t n, T val = T())//val給T類型的缺省值
		{
			if (n > capacity())//n大于capacity，要擴(kuò)容
			{
				reserve(n);
				while (_finish < _start + n)
				{
					*_finish = val;
					++_finish;
				}
			}
			else if (n > size())//n小于capacity但大于原size
			{
				while (_finish < _start + n)
				{
					*_finish = val;
					++_finish;
				}
			}
			else//縮size的情況
			{
				_finish = _start + n;
			}
		}
		//push_back/pop_back接口
		void push_back(const T& val)
		{
			if (_finish == _end_of_storage)
			{
				size_t newCapacity = capacity() == 0 ? 4 : 2 * capacity();
				reserve(newCapacity);
			}
			*_finish = val;
			++_finish;
		}
		void pop_back()
		{
			assert(!empty());
			--_finish;
		}
		//insert和erase接口
		iterator insert(iterator pos, const T& val)
		{
			assert(pos >= _start && pos <= _finish);
			//判斷擴(kuò)容
			if (_finish == _end_of_storage)
			{
				size_t len = pos - _start;//需要處理pos迭代器失效問(wèn)題，記錄len
				size_t newCapacity = capacity() == 0 ? 4 : 2 * capacity();
				reserve(newCapacity);//擴(kuò)容后pos迭代器失效
				pos = _start + len;//重新設(shè)定pos
			}
			//挪動(dòng)數(shù)據(jù)
			for (iterator i = _finish; i > pos; --i)
			{
				*i = *(i - 1);
			}
			//填入數(shù)據(jù)
			*pos = val;
			++_finish;
			return pos;
		}
		iterator erase(iterator pos)
		{
			assert(pos >= _start && pos <= _finish);
			for (iterator i = pos; i < _finish - 1; ++i)
			{
				*pos = *(pos + 1);
			}
			--_finish;
			return pos;
		}
		//小接口
		size_t size()const
		{
			return _finish - _start;
		}
		size_t capacity()const
		{
			return _end_of_storage - _start;
		}
		bool empty()const
		{
			return _start == _finish;
		}
		void clear()
		{
			_finish = _start;
		}
	private:
		iterator _start;
		iterator _finish;
		iterator _end_of_storage;
	};
 
 
 
/測(cè)試部分
	void test()
	{
		vector<int> v(1, 5);
		vector<int> v1(v);
		for (auto e : v1)
		{
			cout << e << " ";
		}
	}
	class Solution {
	public:
		vector<vector<int>> generate(int numRows) {
			vector<vector<int>> vv;
			vv.resize(numRows);
			for (size_t i = 0; i < vv.size(); ++i)
			{
				vv[i].resize(i + 1, 0);
				vv[i][0] = vv[i][vv[i].size() - 1] = 1;
			}
 
			for (size_t i = 0; i < vv.size(); ++i)
			{
				for (size_t j = 0; j < vv[i].size(); ++j)
				{
					if (vv[i][j] == 0)
					{
						vv[i][j] = vv[i - 1][j] + vv[i - 1][j - 1];
					}
				}
			}
			for (size_t i = 0; i < vv.size(); ++i)
			{
				for (size_t j = 0; j < vv[i].size(); ++j)
				{
					cout << vv[i][j] << " ";
				}
				cout << endl;
			}
			return vv;
		}
	};
	void test_vector()
	{
		vector<vector<int>> vv;
		vector<int> v(5, 1);
		vv.push_back(v);
		vv.push_back(v);
		vv.push_back(v);
		vv.push_back(v);
		vv.push_back(v);
 
		for (size_t i = 0; i < vv.size(); ++i)
		{
			for (size_t j = 0; j < vv[i].size(); ++j)
			{
				cout << vv[i][j] << " ";
			}
			cout << endl;
		}
		cout << endl;
	}
}