// vector.h
#pragma once
#include <assert.h>
// 模擬實(shí)現(xiàn) -- 加深對(duì)這個(gè)容器理解，不是為了造更好的輪子
namespace Yuucho
{
	template<class T>
	class vector
	{
	public:
		typedef T* iterator;
		typedef const T* const_iterator;
		vector()
			:_start(nullptr)
			, _finish(nullptr)
			, _endofstorage(nullptr)
		{}
        // 迭代器區(qū)間來(lái)構(gòu)造，用模板的原因是存儲(chǔ)的類(lèi)型多種多樣
        template <class InputIterator>
		vector(InputIterator first, InputIterator last)
			: _start(nullptr)
			, _finish(nullptr)
			, _endofstorage(nullptr)
		{
			while (first != last)
			{
				push_back(*first);
				++first;
			}
		}
        // 用n個(gè)T去構(gòu)造，但是會(huì)隱藏匹配問(wèn)題
        vector(size_t n, const T& val = T())
			: _start(nullptr)
			, _finish(nullptr)
			, _endofstorage(nullptr)
		{
			reserve(n);
			for (size_t i = 0; i < n; ++i)
			{
				push_back(val);
			}
		}
        void swap(vector<T>& v)
		{
			std::swap(_start, v._start);
			std::swap(_finish, v._finish);
			std::swap(_endofstorage, v._endofstorage);
		}
        //拷貝構(gòu)造函數(shù)
        vector(const vector<T>& v)
			: _start(nullptr)
			, _finish(nullptr)
			, _endofstorage(nullptr)
		{
			vector<T> tmp(v.begin(), v.end());
			swap(tmp);
		}
		// 拷貝賦值函數(shù)
		vector<T>& operator=(vector<T> v)
		{
			swap(v);
			return *this;
		}
        // 資源管理
        ~vector()
        {
            if(_start)
            {
                delete[] _start;
                _start = _finish = _endofstorage = nullptr;
            }
        }
		iterator begin()
		{
			return _start;
		}
		iterator end()
		{
			return _finish;
		}
		const_iterator begin() const
		{
			return _start;
		}
		const_iterator end() const
		{
			return _finish;
		}
		// 默認(rèn)是內(nèi)聯(lián)，頻繁調(diào)用不用擔(dān)心棧幀消耗
		size_t size() const
		{
			return _finish - _start;
		}
		size_t capacity() const
		{
			return _endofstorage - _start;
		}
		void reserve(size_t n)
		{
		}
		//void resize(size_t n, const T& val = T())
		void resize(size_t n, T val = T())
		{
		}
		void push_back(const T& x)
		{
		}
		void pop_back()
		{
		}
		T& operator[](size_t pos)
		{
			assert(pos < size());
			return _start[pos];
		}
		const T& operator[](size_t pos) const
		{
			assert(pos < size());
			return _start[pos];
		}
		iterator insert(iterator pos, const T& x)
		{
		}
        void clear()
        {
            _finish = _start;
        }
	private:
		iterator _start;
		iterator _finish;
		iterator _endofstorage;
	};
}

void reserve(size_t n)
{
    // 一般不考慮縮容(n<capacity)
    if(n > capacity())
    {
        T* tmp = new T[n];
    	// capacity為0,n就是4(_endofstorage、_start都為nuptr)
        // 有數(shù)據(jù)才拷貝
        if(_start)
        {
            memcpy(tmp, _start, size()*sizeof(T));
        	delete[] _start;
        }
        _start = tmp; // 注意,這里start位置變了
    }
    // 更新_finish、_endofstorage
    _finish = _start + size();  // size():_finish - _start, _finish還是空指針
    _endofstorage = _start + capacity;  //capacity起始為0,也不對(duì)
}

void reserve(size_t n)
{
    // 記錄size
    size_t sz = size();
    if(n > capacity())
    {
        T* tmp = new T[n];
        if(_start)
        {
            //memcpy還會(huì)隱藏更深層次的深淺拷貝問(wèn)題，講解在最后
            memcpy(tmp, _start, size()*sizeof(T));
        	delete[] _start;
        }
        _start = tmp; // 注意,這里start位置變了
    }
    // 更新_finish、_endofstorage
    _finish = _start + sz;  
    _endofstorage = _start + n;
}

//void resize(size_t n, const T& val = T())  嚴(yán)格的編譯器編不過(guò),它認(rèn)為T(mén)是臨時(shí)對(duì)象
// 按照庫(kù)里的寫(xiě)法
void resize(size_t n, T val = T())  // T類(lèi)型的匿名對(duì)象，默認(rèn)構(gòu)造函數(shù)很重要,內(nèi)置類(lèi)型咋辦？
{
    if (n > capacity())
	{
		reserve(n);
	}
	if (n > size())
    {
		while (_finish < _start + n)
		{
			*_finish = val;
			++_finish;
		}
	}
    // n < capacity就是刪除數(shù)據(jù)
	else
	{
		_finish = _start + n;
	}
}

void push_back(const T& x)
{
    // 滿(mǎn)了先擴(kuò)容
    if(_finish == _endofstorage)
    {
        size_t newCapacity = capacity() == 0 ? 4 : capacity() * 2;
        reserve(newCapacity);
    }
    // 插入數(shù)據(jù)
    *_finish = x;
    ++_finish;
}

void push_back(const T& x)
{
    insert(end(), x);
}

void pop_back()
{
    // 如果不為空
    if(_finish > _start)
    {
        --_finish;
    }
}

void pop_back()
{
    erase(end()-1);
}

void insert(iterator pos, const T& x)
{
	// 檢查參數(shù)
	assert(pos >= _start && pos <= _finish);
	// 擴(kuò)容
	if (_finish == _endofstorage)
	{
		size_t newCapacity = capacity() == 0 ? 4 : capacity() * 2;
		reserve(newCapacity);
	}
	// 挪動(dòng)數(shù)據(jù)
	iterator end = _finish - 1;
	while (end >= pos)
	{
		*(end + 1) = *end;
		--end;
	}
	*pos = x;
	++_finish;
}

if (_finish == _endofstorage)
{
	size_t n = pos - _start;
	size_t newCapacity = capacity() == 0 ? 4 : capacity() * 2;
	reserve(newCapacity);
	pos = _start + n;
}

	void test_vector1()
	{
		// 在所有的偶數(shù)的前面插入2
		vector<int> v;
		//v.reserve(10);
		v.push_back(1);
		v.push_back(2);
		v.push_back(3);
		v.push_back(4);
		v.push_back(5);
		v.push_back(6);
		vector<int>::iterator it = v.begin();
		while (it != v.end())
		{
			if (*it % 2 == 0)
			{
				it = v.insert(it, 20);
				++it;
			}
			++it;
		}
		for (auto e : v)
		{
			cout << e << " ";
		}
		cout << endl;
	}
}

iterator insert(iterator pos, const T& x)
{
	// 檢查參數(shù)
	assert(pos >= _start && pos <= _finish);
	// 擴(kuò)容
	// 擴(kuò)容以后pos就失效了,需要更新一下
	if (_finish == _endofstorage)
	{
		size_t n = pos - _start;
		size_t newCapacity = capacity() == 0 ? 4 : capacity() * 2;
		reserve(newCapacity);
		pos = _start + n;
	}
	// 挪動(dòng)數(shù)據(jù)
	iterator end = _finish - 1;
	while (end >= pos)
	{
		*(end + 1) = *end;
		--end;
	}
	*pos = x;
	++_finish;
	return pos;
}

while (it != v.end())
{
    if(*it % 2 == 0)
    {
        // 返回新插入的第一個(gè)元素的迭代器
        it = v.insert(it, 20);
        //還是指向2
        ++it;
    }
    // 指向2的后一位
    ++it;
}

iterator erase(iterator pos)
{
	assert(pos >= _start && pos < _finish);
	iterator it = pos + 1;
	while (it != _finish)
	{
		*(it - 1) = *it;
		++it;
	}
	//erase最后一個(gè)數(shù)據(jù)，則pos==_finish，pos真失效了，但仍然屬于這個(gè)容器
	--_finish;
	return pos;
}

vector(int n, const T& val = T())
			: _start(nullptr)
			, _finish(nullptr)
			, _endofstoage(nullptr)
		{
			reserve(n);
			for (int i = 0; i < n; ++i)
			{
				push_back(val);
			}
		}

class Solution {
public:
    vector<vector<int>> generate(int numRows) {
    vector<vector<int>> vv;
    // 先開(kāi)辟楊輝三角的空間
    vv.resize(numRows);
    //初始化每一行
    for(size_t i = 0; i < numRows; ++i)
    {
        //每行個(gè)數(shù)依次遞增
        vv[i].resize(i+1, 0);
        // 每一行的第一個(gè)和最后一個(gè)都是1
        vv[i][0] = 1;
        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)
            {
                //之間位置等于上一行j-1和j個(gè)相加
                vv[i][j] = vv[i-1][j-1] + vv[i-1][j];
            }
        }
    }
    return vv;
    }
};

void test_vector2()
{
	vector<vector<int>> ret = Solution().generate(5);
	for (size_t i = 0; i < ret.size(); ++i)
	{
		for (size_t j = 0; j < ret[i].size(); ++j)
		{
			cout << ret[i][j] << " ";
		}
		cout << endl;
	}
	cout << endl;
}

void reserve(size_t n)
{
    // 記錄size
    size_t sz = size();
    if(n > capacity())
    {
        T* tmp = new T[n];
        if(_start)
        {
            memcpy(tmp, _start, size()*sizeof(T));
        	delete[] _start;
        }
        _start = tmp; // 注意,這里start位置變了
    }
    // 更新_finish、_endofstorage
    _finish = _start + sz;  
    _endofstorage = _start + n;
}

void reserve(size_t n)
{
    // 記錄size
    size_t sz = size();
    if(n > capacity())
    {
        T* tmp = new T[n];
        if(_start)
        {
            //防止淺拷貝問(wèn)題3
           for (size_t i = 0; i < size(); ++i)
			{
				tmp[i] = _start[i];
			}
        	delete[] _start;
        }
        _start = tmp; // 注意,這里start位置變了
    }
    // 更新_finish、_endofstorage
    _finish = _start + sz;  
    _endofstorage = _start + n;
}