目录
列表(list)
初始化(构造函数和分配值)
迭代器
增加元素
删除元素
谓词
其他操作
刚才看了一些vector然后我发现还是很乱,既然都很乱,之后容器还是写的全一点吧.
列表(list)
一个双向链表,相对vector的联系空间,list复杂很多,它可以快速的插入和删除,但是随机访问比较慢.
因为是链表实现,所以他不会造成空间浪费.
初始化(构造函数和分配值)
#include
#include
#include
using namespace std;
int main()
{
//其实容器内的函数都差不多,构造函数基本和vector完全一样
list l; //创建一个空的list
list l2(3); //创建一个含有3个元素的list
list l3(3, 1); //创建一个含有3个元素的list,每个都初始化为1
list l4(l3); //创建一个list,并用l3对齐进行初始化
list l5(l4.begin(), l4.end()); //用迭代器进行初始化
//也可以为其分配值
l.assign(l4.begin(), l4.end());
l2.assign(3, 1); //为其赋值3个1
int arr[] = { 1,2,3,4,5,6,7,8,9,0 };
list l6(arr, arr + 10); //使用数组对其进行初始化
//遍历
//for (list::iterator it = l5.begin(); it != l5.end(); ++it)
for (auto it = l6.begin(); it != l6.end(); ++it)
{
cout << *it << " ";
}
cout << endl;
//定义一个迭代器
auto it = l6.begin();
vector v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
auto it2 = v.begin();
//it + 2; //错误不支持随机访问
it2 + 2; //correct
cout << *(it2 + 2) << endl;
return 0;
}
迭代器
#include
#include
using namespace std;
int main()
{
list l;
int arr[] = { 1,2,3,4,5,6,7,8,9,0 };
l.assign(arr, arr + 10);
//正向迭代器
auto it_end = l.end();
//cout << *it_end << endl; //程序会蹦 指向的是最后一个元素的下一位置
auto it_begin = l.begin();
cout << *it_begin << endl; //输出的是第一个元素 1
for (auto it = l.begin(); it != l.end(); ++it)
{
cout << *it << " ";
}
cout << endl;
cout << endl;
cout << endl;
//逆向迭代器
auto rit_end = l.rend();
//cout << *rit_end << endl; //同样会崩 指向第一个元素的上一位置
auto rit_begin = l.rbegin();
cout << *rit_begin << endl; //输出的是最后一个元素 0
for (auto it = l.rbegin(); it != l.rend(); ++it)
{
cout << *it << " ";
}
cout << endl;
return 0;
}
-
#include
#include#include using namespace std; int main() { list
l; int arr[] = { 1,2,3,4,5,6,7,8,9,0 }; l.assign(arr, arr + 10); //正向迭代器 auto it_end = l.end(); //cout << *it_end << endl; //程序会蹦 指向的是最后一个元素的下一位置 auto it_begin = l.begin(); cout << *it_begin << endl; //输出的是第一个元素 1 for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; } cout << endl; cout << endl; cout << endl; //逆向迭代器 auto rit_end = l.rend(); //cout << *rit_end << endl; //同样会崩 指向第一个元素的上一位置 auto rit_begin = l.rbegin(); cout << *rit_begin << endl; //输出的是最后一个元素 0 for (auto it = l.rbegin(); it != l.rend(); ++it) { cout << *it << " "; } cout << endl; return 0; }
逆向迭代器,和这些规则vector也同样遵守.
增加元素
#include
#include
#include
using namespace std;
int main()
{
list l;
int arr[] = { 1,2,3,4,5 };
vector v(arr, arr + 5);
//后插
l.push_back(1);
//前插
l.push_front(2); //2 1
//插入 插入到迭代器位置 返回插入迭代器位置
auto it = l.insert(l.begin(), 3); //3 2 1
cout << *it << endl; //3
//插入3个1到迭代器位置 无返回值
l.insert(l.begin(), 3, 1); //111321
//插入迭代器区间数据到迭代器位置
l.insert(l.begin(), arr, arr + 5); //12345111321
l.insert(l.begin(), v.begin(), v.end()); //1234512345111321
for (auto it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //1234512345111321
}
cout << endl;
return 0;
}
删除元素
谓词
-
#include
谓词
返回值为bool类型的函数,仿函数就是谓词.一个参数的是一元谓词,两个参数就是二元谓词
#include#include using namespace std; //函数形式谓词 bool func(int& val) { return val < 6; } //仿函数形式谓词 class functor { public: bool operator()(int& val) { return val < 6; } }; bool func2(int val, int val2) { return val > val2; } int main() { int arr[] = { 1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9,0 }; list
l(arr, arr + 20); //删除迭代器指定位置 l.erase(l.begin()); //23456789012345 //删除指定迭代器区间 auto it = l.begin(); it++; it++; //it + 1; 不能随机访问的迭代器这样加1也是不可以的 l.erase(l.begin(), it); //45678901234567890 for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; //45678901234567890 } cout << endl; //按值删除元素,删除list所有这个值的元素 l.remove(4); //567890123567890 //按条件删除,需要谓词 //两效果是等价的 //l.remove_if(func); l.remove_if(functor()); //67896789 //删除第一个元素 l.pop_front(); //7896789 //删除最后一个元素 l.pop_back(); //789678 //删除重复元素 只会删除连续重复的 l.unique(); for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; //789678 } cout << endl; l.push_front(7); l.push_front(7); l.push_back(8); l.push_back(8); for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; //7778967888 } cout << endl; l.unique(); for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; //789678 } cout << endl; //删除所有小于前者的元素 l.unique(func2); for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; //789 } cout << endl; //删除所有元素 l.clear(); for (auto it = l.begin(); it != l.end(); ++it) { cout << *it << " "; } cout << endl; return 0; }
其他操作
#include
#include
using namespace std;
bool greaterThan(int val, int val2)
{
return val > val2;
}
int main()
{
list l;
//判断列表是否为空
if (l.empty())
{
cout << "is empty" << endl;
}
int arr[] = { 1,2,3,4,5,6,7,8,9 };
l.insert(l.begin(), arr, arr + 9);
//返回最后一个元素
cout << l.back() << endl; //9
//返回第一个元素
cout << l.front() << endl; //1
//最大元素容量(上限)
cout << l.max_size() << endl;
//list中当前元素个数
cout << l.size() << endl; //9
//改变元素个数
l.resize(5);
for (auto it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //12345
}
cout << endl;
cout << l.size() << endl; //5
//扩充部分用1来初始化
l.resize(10, 1);
for (auto it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //1234511111
}
cout << endl;
cout << l.size() << endl; //10
//排序 默认升序 可以使用谓词改变
l.sort();
for (auto it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //1111112345
}
cout << endl;
//降序
l.sort(greaterThan);
for (auto it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //5432111111
}
cout << endl;
//合并 必须是两个有序的列表
list l2 = { 2,3,4,5,6,6,2,34,5,2 };
l2.sort();
l.sort();
//默认也是升序 要和原本容器顺序相同 合并之后l2为空
l.merge(l2);
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //1 1 1 1 1 1 2 2 2 2 3 3 4 4 5 5 5 6 6 34
}
cout << endl;
cout << l2.size() << endl; //0
//降序合并同样需要谓词
l2 = { 5,2,3,4,5,1,2,9 };
l.sort(greaterThan);
l2.sort(greaterThan);
l.merge(l2, greaterThan);
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //34 9 6 6 5 5 5 5 5 4 4 4 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1
}
cout << endl;
cout << l2.size() << endl; //0
//拼接两个list l2会清空元素
l2 = { 5,2,3,4,5,1,2,9 };
//在迭代器位置,插入链表l2
l.splice(l.begin(), l2);
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //5 2 3 4 5 1 2 9 34 9 6 6 5 5 5 5 5 4 4 4 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1
}
cout << endl;
cout << l2.size() << endl; //0
//在迭代器位置,插入链表l2中迭代器的元素
l2 = { 5,2,3,4,5,1,2,9 };
l.splice(l.begin(), l2, l2.begin());
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //5 5 2 3 4 5 1 2 9 34 9 6 6 5 5 5 5 5 4 4 4 3 3 3 2 2 2 2 2 2 1 1 1 1 1 1 1
}
cout << endl;
//在迭代器位置,插入列表的一个迭代器区间
l.clear();
l = { 2,43,24,1342,4 };
l2 = { 5,2,3,4,5,1,2,9 };
l.splice(l.begin(), l2, l2.begin(), l2.end());
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //5 2 3 4 5 1 2 9 2 43 24 1342 4
}
cout << endl;
//list元素倒转
l.reverse();
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //5 2 3 4 5 1 2 9 2 43 24 1342 4
}
cout << endl;
//交换两个list
l2 = { 1,4,5,2,5,6,1 };
l.swap(l2);
for (list::iterator it = l.begin(); it != l.end(); ++it)
{
cout << *it << " "; //1 4 5 2 6 1
}
cout << endl;
for (list::iterator it = l2.begin(); it != l2.end(); ++it)
{
cout << *it << " "; //5 2 3 4 5 1 2 9 2 43 24 1342 4
}
cout << endl;
return 0;
}
-
using namespace std;
bool greaterThan(int val, int val2)
{
return val > val2;
}
int main()
{
list
