143.vector模板库

• myvector.h

   1 #pragma once
   2 #include <initializer_list>
   3 #include <iostream>
   4 using namespace std;
   5
   6 template<class T>
   7 class myvector
   8 {
   9 public:
  10     myvector();
  11     myvector(int n);
  12     myvector(initializer_list<T> my);
  13     void show() const;
  14     ~myvector();
  15     //用于迭代
  16     T *begin();
  17     T *end();
  18     int arraysize();
  19     int memsize();
  20     //后插
  21     void push_back(T data);
  22     //前插
  23     void push_front(T data);
  24     //返回的是副本
  25     T operator[](int i) const;
  26     //返回的不是副本
  27     T &operator[](int i);
  28     //发现左值
  29     T* find(T &t);
  30     //发现右值
  31     T* find(T &&t);
  32     //改变一个值,传递的是右值
  33     void change(T *pos, T &&t);
  34     //改变一个值,传递的是左值
  35     void change(T *pos, T &t);
  36     void del(T &t);
  37     void del(T &&t);
  38     //找到的位置之前插入
  39     void insert(T &t, T &newt);
  40     void insert(T &&t, T &&newt);
  41
  42     template<class T>
  43     friend ostream& operator <<(ostream &out, myvector<T> &myv);
  44 public:
  45     T * p;
  46     int memn;//内存长度
  47     int realn;//数组长度
  48 };

• myvector.cpp

    1 #include "myvector.h"
    2
    3 template<class T>
    4 myvector<T>::myvector():p(nullptr),memn(0),realn(0)
    5 {
    6
    7 }
    8
    9 template<class T>
   10 myvector<T>::myvector(int n)
   11 {
   12     this->memn = this->realn = n;
   13     this->p = new T[n];
   14     memset(this->p, 0, sizeof(T)*n);
   15 }
   16
   17 template<class T>
   18 myvector<T>::myvector(initializer_list<T> my)
   19 {
   20     this->realn = this->memn = my.size();
   21     this->p = new T[my.size()];
   22     int id = 0;
   23     //初始化
   24     for (auto i : my)
   25     {
   26         this->p[id] = i;
   27         id++;
   28     }
   29 }
   30
   31 template<class T>
   32 void myvector<T>::show() const
   33 {
   34     for (int i = 0; i < realn; i++)
   35     {
   36         cout << p[i];
   37     }
   38 }
   39
   40 template<class T>
   41 myvector<T>::~myvector()
   42 {
   43     if (p != nullptr)
   44     {
   45         delete[] this->p;
   46     }
   47 }
   48
   49 template<class T>
   50 T * myvector<T>::begin()
   51 {
   52     return this->p;
   53 }
   54
   55 template<class T>
   56 T * myvector<T>::end()
   57 {
   58     return this->p + this->realn;
   59 }
   60
   61 template<class T>
   62 int myvector<T>::arraysize()
   63 {
   64     return this->realn;
   65 }
   66
   67 template<class T>
   68 int myvector<T>::memsize()
   69 {
   70     return this->memn;
   71 }
   72
   73 template<class T>
   74 void myvector<T>::push_back(T data)
   75 {
   76     if (this->p == nullptr || this->memn == 0)
   77     {
   78             p = new T;
   79             *p = data;
   80             memn = 1;
   81             realn = 1;
   82     }
   83     else if(memn == realn)
   84     {
   85         T *ptemp = new T[this->memn + 1];
   86         memcpy(ptemp, this->p, this->realn * sizeof(T));
   87         *(ptemp + realn) = data;
   88         delete[] this->p;
   89         this->p = ptemp;
   90         realn += 1;
   91         memn += 1;
   92     }
   93     else
   94     {
   95         p[realn] = data;
   96         realn++;
   97     }
   98 }
   99
  100 template<class T>
  101 void myvector<T>::push_front(T  data)
  102 {
  103     if (this->p == nullptr || this->memn == 0)
  104     {
  105         p = new T;
  106         *p = data;
  107         memn = 1;
  108         realn = 1;
  109     }
  110     else if (memn == realn)
  111     {
  112         T *ptemp = new T[this->memn + 1];
  113         memcpy(ptemp + 1, this->p, this->realn * sizeof(T));
  114         *ptemp = data;
  115         delete[] this->p;
  116         this->p = ptemp;
  117         realn += 1;
  118         memn += 1;
  119     }
  120     else
  121     {
  122         for (int i = 0; i < realn; i++)
  123         {
  124             p[i + 1] = p[i];
  125         }
  126         p[0] = data;
  127         realn += 1;
  128     }
  129 }
  130
  131 template<class T>
  132 T myvector<T>::operator[](int i) const
  133 {
  134     if (i > realn)
  135     {
  136         throw 1;
  137     }
  138     return this->p[i];
  139 }
  140
  141 template<class T>
  142 T & myvector<T>::operator[](int i)
  143 {
  144     if (i > realn)
  145     {
  146         throw 2;
  147     }
  148     return this->p[i];
  149 }
  150
  151 template<class T>
  152 T * myvector<T>::find(T & t)
  153 {
  154     for (auto ib = this->begin(); ib != this->end(); ib++)
  155     {
  156         if (*it == t)
  157         {
  158             return ib;
  159         }
  160     }
  161 }
  162
  163 template<class T>
  164 T * myvector<T>::find(T && t)
  165 {
  166     for (auto ib = this->begin(); ib != this->end(); ib++)
  167     {
  168         if (*it == t)
  169         {
  170             return ib;
  171         }
  172     }
  173 }
  174
  175 template<class T>
  176 void myvector<T>::change(T * pos, T && t)
  177 {
  178     if (pos != nullptr)
  179     {
  180         *pos = t;
  181     }
  182 }
  183
  184 template<class T>
  185 void myvector<T>::change(T * pos, T & t)
  186 {
  187     if (pos != nullptr)
  188     {
  189         *pos = t;
  190     }
  191 }
  192
  193 template<class T>
  194 void myvector<T>::del(T & t)
  195 {
  196     int pos = -1;
  197     for (int i = 0; i < this->realn; i++)
  198     {
  199         if (t == *(this->p + i))
  200         {
  201             pos = i;
  202             break;
  203         }
  204     }
  205     if (pos != -1)
  206     {
  207         if (pos == this->realn)
  208         {
  209             this->realn -= 1;
  210         }
  211         else
  212         {
  213             for (int i = pos; i < realn-1; i++)
  214             {
  215                 p[i] = p[i + 1];
  216             }
  217             realn -= 1;
  218         }
  219     }
  220 }
  221
  222 template<class T>
  223 void myvector<T>::del(T && t)
  224 {
  225     int pos = -1;
  226     for (int i = 0; i < this->realn; i++)
  227     {
  228         if (t == *(this->p + i))
  229         {
  230             pos = i;
  231             break;
  232         }
  233     }
  234     if (pos != -1)
  235     {
  236         if (pos == this->realn)
  237         {
  238             this->realn -= 1;
  239         }
  240         else
  241         {
  242             for (int i = pos; i < realn - 1; i++)
  243             {
  244                 p[i] = p[i + 1];
  245             }
  246             realn -= 1;
  247         }
  248     }
  249 }
  250
  251
  252 template<class T>
  253 void myvector<T>::insert(T & t, T & newt)
  254 {
  255     int pos = -1;
  256     for (int i = 0; i < this->realn; i++)
  257     {
  258         if (t == *(this->p + i))
  259         {
  260             pos = i;
  261             break;
  262         }
  263     }
  264
  265     if (pos != -1)
  266     {
  267         if (this->realn == this->memn)
  268         {
  269                 T *ptemp = new T[this->memn + 1];
  270                 memcpy(ptemp, this->p, sizeof(T)*memn);
  271
  272                 delete[] this->p;
  273                 this->p = ptemp;
  274                 this->realn += 1;
  275                 this->memn += 1;
  276                 for (int i = realn - 2; i >= pos; i--)
  277                 {
  278                     p[i + 1] = p[i];
  279                 }
  280                 p[pos] = newt;
  281         }
  282         else
  283         {
  284             for (int i = realn - 2; i >= pos; i--)
  285             {
  286                 p[i + 1] = p[i];
  287             }
  288             p[pos] = newt;
  289             this->realn += 1;
  290         }
  291     }
  292
  293 }
  294
  295 template<class T>
  296 void myvector<T>::insert(T && t, T && newt)
  297 {
  298     int pos = -1;
  299     for (int i = 0; i < this->realn; i++)
  300     {
  301         if (t == *(this->p + i))
  302         {
  303             pos = i;
  304             break;
  305         }
  306     }
  307
  308     if (pos != -1)
  309     {
  310         if (this->realn == this->memn)
  311         {
  312             T *ptemp = new T[this->memn + 1];
  313             memcpy(ptemp, this->p, sizeof(T)*memn);
  314
  315             delete[] this->p;
  316             this->p = ptemp;
  317             this->realn += 1;
  318             this->memn += 1;
  319             for (int i = realn - 2; i >= pos; i--)
  320             {
  321                 p[i + 1] = p[i];
  322             }
  323             p[pos] = newt;
  324         }
  325         else
  326         {
  327             for (int i = realn - 2; i >= pos; i--)
  328             {
  329                 p[i + 1] = p[i];
  330             }
  331             p[pos] = newt;
  332             this->realn += 1;
  333         }
  334     }
  335 }
  336
  337 template<class T>
  338 ostream & operator<<(ostream & out, myvector<T> & myv)
  339 {
  340     for (int i = 0; i < myv.realn; i++)
  341     {
  342         out << myv.p[i];
  343     }
  344     return out;
  345 }

• main.cpp

   1 #include "myvector.h"
   2 #include "myvector.cpp"
   3
   4 void main()
   5 {
   6     myvector<double> myv({ 1.1,2.2,3.3 });
   7     //myv.show();
   8     ////迭代器
   9     //for (auto i : myv)
  10     //{
  11     //    cout << i << endl;
  12     //}
  13     myv.push_front(4.4);
  14     myv.push_back(5.5);
  15     myv.insert(2.2, 8.8);
  16     myv.del(2.2);
  17     myv.push_back(2.2);
  18     myv.del(2.2);
  19     /*for (auto ib = myv.begin(), ie = myv.end(); ib != ie; ib++)
  20     {
  21         cout << *ib << endl;
  22     }*/
  23     //cout << myv[1] << endl;
  24     cout << myv << endl;
  25     myv.show();
  26     cin.get();
  27 }

原文地址：https://www.cnblogs.com/xiaochi/p/8711425.html