运用到的知识：（不分先后）
模板，类，循环数组，线性表，指针，异常，迭代器，输入输出等C++基础
#include<iterator>
#include<iostream>
#include<vector>
#include<cstring>
#include<string>
using namespace std;class EmptyListException :public exception
{
public:EmptyListException(){}
};
class InvalidIteratorException :public exception
{
public:InvalidIteratorException(){}
};template<class T>
class ArrayList {public:class Iterator : public iterator <input_iterator_tag, T> {public:Iterator(T* p,T* elem,int cnt) {_ptr = p;selfElems = elem;count = cnt;}bool operator != (const Iterator &iter) {return _ptr!= iter._ptr;}bool operator == (const Iterator &iter) {return _ptr == iter._ptr;}Iterator& operator ++ () {_ptr++;if(_ptr >= selfElems+count) _ptr = selfElems;return *this;}Iterator& operator -- () {_ptr--;if(_ptr < 0) _ptr = selfElems+count-1;return *this;}Iterator operator ++ (int) {Iterator tmp= *this;_ptr++;if(_ptr >= selfElems+count) _ptr = selfElems;return tmp;}Iterator operator -- (int) {Iterator tmp= *this;_ptr--;if(_ptr < 0) _ptr = selfElems+count-1;return tmp;}T& operator * () {return *_ptr;}public:T* _ptr;T* selfElems;int count;};ArrayList() {_selfElems = new T[4];_count = 4;init();}ArrayList(int n) {_selfElems = new T[n];_count = n;init();}~ArrayList() {delete[] _selfElems;}void init() {_front=0;_back=-1;nowsize = 0;}T& operator[](int i) {return _selfElems[i];}Iterator begin() {return Iterator(_selfElems+_front,_selfElems,_count);}Iterator end() {return Iterator(_selfElems + (_back + 1)%_count,_selfElems,_count);}T& front() {return _selfElems[_front];}T& back() {return _selfElems[_back];}int size() const {return nowsize;}void insertFront(T& e) {if(nowsize == _count) {T* _selfElems2 = new T[_count*2];for(int i = 0; i<_count; i++) {_selfElems2[i] = _selfElems[(_front+i)%_count];}delete[] _selfElems;_selfElems = _selfElems2;_front=0;_back=_count-1;_count*=2;}if(_front == 0) _front=_count-1;else _front--;_selfElems[_front] = e;nowsize++;}void insertBack(T&e) {if(nowsize == _count) {T* _selfElems2 = new T[_count*2];for(int i = 0; i<_count; i++) {_selfElems2[i] = _selfElems[(_front+i)%_count];}delete[] _selfElems;_selfElems = _selfElems2;_front=0;_back=_count-1;_count*=2;}_back = (_back+1) % _count;_selfElems[_back] = e;nowsize++;}void insert(Iterator p, T& e) {if(p._ptr < _selfElems || p._ptr >= _selfElems+_count||(begin()._ptr < end()._ptr && (p._ptr < begin()._ptr || p._ptr >= end()._ptr)) || (begin()._ptr > end()._ptr && (p._ptr < begin()._ptr && p._ptr >= end()._ptr))) {throw InvalidIteratorException();}if(nowsize == _count) {T* _selfElems2 = new T[_count*2];for(int i = 0; i<_count; i++) {_selfElems2[i] = _selfElems[(_front+i)%_count];}delete[] _selfElems;_selfElems = _selfElems2;_front=0;_back=_count-1;_count*=2;}int pos = p._ptr - begin().ptr;int len = (_back-1)-(pos+_front);for(int i = len; i>=0; i++) {int tar = i + pos+_front;_selfElems[(tar+1)%_count] = _selfElems[tar%_count];}_selfElems[pos+_front] = e;nowsize++;}void removeFront() {if(nowsize == 0) {throw EmptyListException();}_front = (_front+1)%_count;nowsize--;}void removeBack() {if(nowsize == 0) {throw EmptyListException();}_back = (_back+_count-1)%_count;nowsize--;}void remove(Iterator p) {if(nowsize == 0) {throw EmptyListException();}if(p._ptr < _selfElems || p._ptr >= _selfElems+_count||(begin()._ptr < end()._ptr && (p._ptr < begin()._ptr || p._ptr >= end()._ptr)) || (begin()._ptr > end()._ptr && (p._ptr < begin()._ptr && p._ptr >= end()._ptr))) {throw InvalidIteratorException();}int pos = p._ptr - begin()._ptr;//pos+_front ~ (back-1)int len = (_back-1)-(pos+_front);for(int i = 0; i<len; i++) {int tar = i + pos+_front;_selfElems[tar%_count] = _selfElems[(tar+1)%_count];}nowsize--;}private:int _count;int _front,_back,nowsize;T* _selfElems;};void testArrayListUnderflow() {// the first try blocktry {ArrayList<int> arr;int x = 1;arr.insertBack(x);arr.removeFront();arr.removeFront();printf("did not catch exception\n");} catch(EmptyListException& e) {printf("caught EmptyStackException\n");}// the second try blocktry {ArrayList<int> arr;int x = 1;arr.insertBack(x);arr.removeBack() ;arr.removeBack() ;printf("did not catch exception\n");} catch(EmptyListException& e) {printf("caught EmptyStackException\n");}// the third try blocktry {ArrayList<int> arr;int x = 1;arr.insertBack(x);ArrayList<int>::Iterator it = arr.begin();arr.remove(it);it = arr.begin();arr.remove(it);printf("did not catch exception\n");} catch(EmptyListException& e) {printf("caught EmptyStackException\n");}
}
void testIntegerIterator() {ArrayList<int> arr;int a[6] = {1,2,3,4,5,6};for(int i = 0; i<6; i++) arr.insertBack(a[i]);for(ArrayList<int>::Iterator iter = arr.begin(); iter != arr.end(); iter++) {cout << *iter << " ";}cout << endl;arr.removeFront();arr.removeFront();arr.removeFront();int b[3] = {7,8,9};arr.insertBack(b[0]);arr.insertBack(b[1]);arr.insertBack(b[2]);for(ArrayList<int>::Iterator iter = arr.begin(); iter != arr.end(); iter++) {cout << *iter << " ";}cout << endl;
}
void testStringIterator() {ArrayList<string> arr;string a[6] = {"s1","s2","s3","s4","s5","s6"};for(int i = 0; i<6; i++) arr.insertBack(a[i]);for(ArrayList<string>::Iterator iter = arr.begin(); iter != arr.end(); iter++) {cout << *iter << " ";}cout << endl;arr.removeFront();arr.removeFront();arr.removeFront();string b[3] = {"s7","s8","s9"};arr.insertBack(b[0]);arr.insertBack(b[1]);arr.insertBack(b[2]);for(ArrayList<string>::Iterator iter = arr.begin(); iter != arr.end(); iter++) {cout << *iter << " ";}cout << endl;
}
int main() {testArrayListUnderflow();testIntegerIterator();testStringIterator();return 0;
}参考资料：
http://c.biancheng.net/view/471.html
https://blog.csdn.net/holyweng/article/details/82821646
https://blog.csdn.net/qq_36745117/article/details/83863190
https://blog.csdn.net/XiaoHeiBlack/article/details/77014626
