list

list

双向列表,链式存储

1 生成构造

// constructing lists
#include <iostream>
#include <list>

int main ()
{
  // constructors used in the same order as described above:
  std::list<int> first;                                // empty list of ints
  std::list<int> second (4,100);                       // four ints with value 100
  std::list<int> third (second.begin(),second.end());  // iterating through second
  std::list<int> fourth (third);                       // a copy of third

  // the iterator constructor can also be used to construct from arrays:
  int myints[] = {16,2,77,29};
  std::list<int> fifth (myints, myints + sizeof(myints) / sizeof(int) );

  std::list<int> first (3);      // list of 3 zero-initialized ints
  std::list<int> second (5);     // list of 5 zero-initialized ints

  second = first;//second size is 3

  return 0;
}

2 操作

2.1 大小和容量

/*
 * size  max_size    empty resize
*/
#include <iostream>
#include <list>

int main ()
{
  //capacity
    std::list<int> mylist(5,1);
    mylist.size();      //size is 5
    mylist.max_size();
    mylist.resize(10);
    mylist.empty();     //0

  return 0;
}

2.2 比较

2.3 find

2.4 截取部分

2.5 增,插,删,改

/*
 * modify  element
 * assign       pop_back    pop_front
 * push_back    push_front  insert
 * erase        clear       swap
*/
#include <iostream>
#include <list>

int main ()
{
  //modify elements
    std::list<int> mylist(5,1);
    mylist.assign(3,2);             //mylist={2,2,2}
    mylist.pop_back();
    mylist.pop_front();             //mylist={2}
    mylist.push_back(1);
    mylist.push_front(3);           //mylist={3,2,1}

    mylist.insert(mylist.cbegin(),2);               //mylist={2,3,2,1}
    int ints[]={9,5,2,7};
    mylist.insert(mylist.cbegin(),ints,ints+4);     //mylist={9,5,2,7,2,3,2,1}

    mylist.erase(mylist.begin()); //because is 链式存储,位置还真不好确定,因此remove出现了
    mylist.remove(2);             //delete element of value is 2
    mylist.clear();

    std::list<int> mylist2(3,1);
    mylist.swap(mylist2);


    for(auto it=mylist.cbegin();it!=mylist.cend();it++)
        std::cout<<*it<<' ';
  return 0;
}

2.6元素存取

/*
 * element access
 * back font
*/
#include <iostream>
#include <list>

int main ()
{
  //elemnet access
    std::list<int> mylist(5,1);
    mylist.back();  //1
    mylist.front(); //1
  return 0;
}

2.7其他

// list::merge
//unique去重复
//sort()排序
//reverse()倒置list
#include <iostream>
#include <list>

// compare only integral part:只是考虑整数部分,因此插入位置不是你想的那样按大小排序
bool mycomparison (double first, double second)
{ return ( int(first)<int(second) ); }

int main ()
{
  std::list<double> first, second;

  first.push_back (3.1);
  first.push_back (2.2);
  first.push_back (2.9);

  second.push_back (3.7);
  second.push_back (7.1);
  second.push_back (1.4);

  first.sort();
  second.sort();

  first.merge(second);

  // ( now second is empty)

  second.push_back (2.1);

  first.merge(second,mycomparison);

  std::cout << "first contains:";
  for (std::list<double>::iterator it=first.begin(); it!=first.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}