2799 Simple Life @myLove (eden)

Description

An iterator is any object that, pointing to some element in a range of
elements (such as an array or a container), has the ability to iterate through
the elements of that range using a set of operators (with at least the
increment (++) and dereference (*) operators).

The most obvious form of iterator is a pointer: A pointer can point to
elements in an array, and can iterate through them using the increment
operator (++). But other kinds of iterators are possible. For example, each
container type (such as a list) has a specific iterator type designed to
iterate through its elements.

Details about iterator:
C PLUS PLUS
WIKIPEDIA

Now we are going to make an iterator and find fun!

Carson has written the “simple_vector”, it realizes a little of the functions
in STL_Vector, he invites all of you to design the “simple_iterator.h”.

What is simple_vector:
It is a data structure to store data dynamically.
member: char* data; long long int size, capacity;
function: pushBack(char); Begin(); End(); rBegin(); rEnd();

What is simple_iterator:
member: char* pointer;
function: char& base(), C++11 prev(), next(), begin(), end();
overload: * / ++ / – / == / != / < / > / <= / >= / + / - ;

Note: all the input data are from ‘a’ to ‘z’, and the vector’s size is no less than 5 in this test.

From: 林楚庭

Provided Codes

main.cpp

#include <iostream>#include "simple_vector.h"using namespace std;void test_iterator() {    int t, i;    char c;    simple_vector ivec;    simple_vector::iterator iter, iter1, iter2;    cin >> t;    for (i = 0; i < t; i++) {        cin >> c;        ivec.pushBack(c);    }    cout << "Foward test: ";    for (iter = ivec.Begin(); iter != ivec.End(); ++iter)        cout << *iter;    cout << "\n";    cout << "Backward test: ";    for (iter = ivec.rBegin(); iter != ivec.rEnd(); --iter)        cout << *iter;    cout << "\n";    cout << "Self-Foward test: ";    iter1 = ivec.Begin();    iter2 = ++iter1;    cout << *iter2;    iter1 = ivec.Begin();    iter2 = iter1++;    cout << *iter2 << "\n";    cout << "Self-Backward test: ";    iter1 = ivec.rBegin();    iter2 = --iter1;    cout << *iter2;    iter1 = ivec.rBegin();    iter2 = iter1--;    cout << *iter2 << "\n";    cout << "Compare test#1: ";    iter1 = ivec.Begin();    iter2 = ivec.rBegin();    cout << (iter1 < iter2);    cout << (iter1 > iter2);    cout << (iter1 <= iter2);    cout << (iter1 >= iter2);    cout << (iter1 == iter1);    cout << (iter1 != iter2) << "\n";    cout << "Compare test#2: ";    iter1 = ivec.Begin();    iter2 = ivec.rBegin();    cout << (iter2 < iter1);    cout << (iter2 > iter1);    cout << (iter1 <= iter1);    cout << (iter2 >= iter2);    cout << (iter1 == iter2);    cout << (iter1 != iter1) << "\n";    cout << "Move test: ";    iter1 = ivec.Begin();    iter2 = iter1 + 4;    cout << *iter2;    iter2 = iter2 - 3;    cout << *iter2;    iter2 = iter2 + 2;    cout << *iter2 << "\n";    cout << "C++11 test: ";    iter1 = ivec.Begin();    iter2 = ivec.rBegin();    ++iter1;    cout << *(iter1.begin());    cout << *(iter1.end());    cout << *(iter1.prev());    cout << *(iter1.next());    --iter2;    cout << *(iter2.begin());    cout << *(iter2.end());    cout << *(iter2.prev());    cout << *(iter2.next());}int main() {    test_iterator();    return 0;}

simple_vector.h

#ifndef SIMPLE_VECTOR_H#define SIMPLE_VECTOR_H#include <iostream>#include <cstring>#include "simple_iterator.h"using namespace std;static long long int MAX = 9999999;class simple_vector {    char* data;    long long int size;    long long int capacity;  public:    typedef simple_iterator iterator;    simple_vector() : size(0), capacity(0) {        data = new char[MAX];        data[0] = '\0';        memset(data, '\0', MAX);    }    ~simple_vector() {        clear();    }    void clear() {        delete [] data;        size = capacity = 0;    }    long long int getSize() {        return size;    }    long long int getCapacity() {        return capacity;    }    void pushBack(char c) {        if (capacity == 0)            capacity = 1;        else if (size == capacity)            capacity = capacity * 2;        data[++size] = c;    }    simple_iterator Begin() {        return iterator(data + 1);    }    simple_iterator End() {        return iterator((data + size + 1));    }    simple_iterator rBegin() {        return iterator((data + size));    }    simple_iterator rEnd() {        return iterator(data);    }};#endif

Submission

simple_iterator.h

#ifndef SIMPLE_ITERATOR_H#define SIMPLE_ITERATOR_Hclass simple_iterator{public:    simple_iterator(){}    simple_iterator(const simple_iterator& a){        p=a.p;    }    simple_iterator prev(){        simple_iterator tem;        tem.p=p;        --tem.p;        return tem;    }    simple_iterator next(){        simple_iterator tem;        tem.p=p;        ++tem.p;        return tem;    }    simple_iterator operator++(int){        simple_iterator tem;        tem.p=p;        ++p;        return tem;    }    simple_iterator& operator++(){        ++p;        return *this;    }    simple_iterator operator--(int){        simple_iterator tem;        tem.p=p;        --p;        return tem;    }    simple_iterator& operator--(){        --p;        return *this;    }    char operator*(){        return *p;    }    bool operator==(const simple_iterator& a){        return *p==*a.p;    }    bool operator!=(const simple_iterator& a){        return *p!=*a.p;    }    bool operator<(const simple_iterator& a){        return *p<*a.p;    }    bool operator>(const simple_iterator& a){        return *p>*a.p;    }    bool operator<=(const simple_iterator& a){        return *p<=*a.p;    }    bool operator>=(const simple_iterator& a){        return *p>=*a.p;    }    simple_iterator operator+(int n){        simple_iterator tem;        tem.p=p+n;        return tem;    }    simple_iterator operator-(int n){        simple_iterator tem;        tem.p=p-n;        return tem;    }    simple_iterator& operator=(const simple_iterator& a){        p=a.p;        return *this;    }    simple_iterator begin(){        simple_iterator tem;        tem.p=p;        while(*(tem.p)<256&&*(tem.p)>0)            --tem.p;        ++tem.p;        return tem;    }    simple_iterator end(){        simple_iterator tem;        tem.p=p;        while(*(tem.p)<256&&*(tem.p)>0)            ++tem.p;        --tem.p;        return tem;    }    simple_iterator(char* a){        p=a;    }private:    char* p;};#endif