8.list的使用

一.构造函数以及赋值

二.迭代器部分

三.容量和元素

四.成员函数

五.list的使用

void test_list1()
{list<int> lt1 = { 10,2,3,3,4,3,5,6};list<int>::iterator it = lt1.begin();while (it != lt1.end()){cout << *it << " ";++it;}cout << endl;for (auto e : lt1){cout << e << " ";}cout << endl;//sort(lt1.begin(), lt1.end());lt1.sort();for (auto e : lt1){cout << e << " ";}cout << endl;lt1.sort(greater<int>());for (auto e : lt1){cout << e << " ";}cout << endl;lt1.unique();for (auto e : lt1){cout << e << " ";}cout << endl;
}

但是list是双向迭代器,所以list不能使用std::sort

list里面的sort()使用的是归并排序

六.测试vector和list排序时的性能

void test_op1()
{srand(time(0));const int N = 10000000;list<int> lt1;list<int> lt2;vector<int> v;for (int i = 0; i < N; ++i){auto e = rand() + i;lt1.push_back(e);v.push_back(e);}int begin1 = clock();// 排序sort(v.begin(), v.end());int end1 = clock();int begin2 = clock();lt1.sort();int end2 = clock();printf("vector sort:%d\n", end1 - begin1);printf("list sort:%d\n", end2 - begin2);
}

几乎vector排序的销毁几乎是list的3倍

void test_op2()
{srand(time(0));const int N = 10000000;list<int> lt1;list<int> lt2;for (int i = 0; i < N; ++i){auto e = rand()+i;lt1.push_back(e);lt2.push_back(e);}int begin1 = clock();// 拷贝vectorvector<int> v(lt2.begin(), lt2.end());// 排序sort(v.begin(), v.end());// 拷贝回lt2lt2.assign(v.begin(), v.end());int end1 = clock();int begin2 = clock();lt1.sort();int end2 = clock();printf("list copy vector sort copy list sort:%d\n", end1 - begin1);printf("list sort:%d\n", end2 - begin2);
}

上面这个是先将list拷贝到vector排序完之后再拷贝会到list,结果用时还少

七.splice接口使用

int main()
{std::list<int> mylist1, mylist2;std::list<int>::iterator it;// set some initial values:for (int i = 1; i <= 4; ++i)mylist1.push_back(i);      // mylist1: 1 2 3 4for (int i = 1; i <= 3; ++i)mylist2.push_back(i * 10);   // mylist2: 10 20 30it = mylist1.begin();++it;                         // points to 2mylist1.splice(it, mylist2); // mylist1: 1 10 20 30 2 3 4// mylist2 (empty)// "it" still points to 2 (the 5th elementreturn 0;
}

自己插入自己,如下:

int main()
{std::list<int> mylist1;for (int i = 1; i <= 4; ++i)mylist1.push_back(i);      // mylist1: 1 2 3 4auto it = find(mylist1.begin(), mylist1.end(), 3);mylist1.splice(mylist1.begin(), mylist1, it);return 0;
}

如果要将后面的全部转移,就不要写三个参数了,只转移一个就要写第三个参数

#include <iostream>
#include <list>using namespace std;// 打印链表内容的辅助函数
void printList(const list<int>& l, const string& name) {cout << name << ": ";for (int num : l) {cout << num << " ";}cout << endl;
}int main() {list<int> list1 = {1, 2, 3};list<int> list2 = {4, 5, 6};printList(list1, "list1初始值");printList(list2, "list2初始值");// 1. 将list2的所有元素转移到list1的末尾list1.splice(list1.end(), list2);printList(list1, "list1转移后");  // 1 2 3 4 5 6printList(list2, "list2转移后");  // 空// 重新给list2赋值list2 = {7, 8, 9};printList(list2, "list2重新赋值");  // 7 8 9// 2. 将list2中第一个元素转移到list1的开头list1.splice(list1.begin(), list2, list2.begin());printList(list1, "list1转移单个元素后");  // 7 1 2 3 4 5 6printList(list2, "list2转移单个元素后");  // 8 9// 3. 将list2的所有元素转移到list1中值为3的元素前面auto it = find(list1.begin(), list1.end(), 3);if (it != list1.end()) {list1.splice(it, list2, list2.begin(), list2.end());}printList(list1, "list1转移范围元素后");  // 7 1 2 8 9 3 4 5 6printList(list2, "list2转移范围元素后");  // 空return 0;
}