C++ list数据删除、list资料访问、list反转链表、list数据排序

list数据删除，代码见下

#include
#include

using namespace std;

void printList(const list<int>& l) {
for (list<int>::const_iterator it = l.begin(); it != l.end(); it++) {
cout << *it << " ";
}
cout << endl;
}

/*
1 pop_front
2 pop_back
3 erase clear
*/

int main() {
list<int> l = { -1,
 3,
 4,
 7,
 9,
 -1 };
l.pop_back();
printList(l);
l.pop_front();
printList(l);

list<int>::iterator it = l.erase(l.begin());
printList(l);
cout << *it << endl;
it = l.erase(it);
printList(l);
cout << *it << endl;

it++;
it++;
l.erase(it, l.end());
printList(l);

l.clear();
printList(l);

cout << "l.size()= " << l.size() << endl;
return 0;
}

结果见下，助理解

-1 3 4 7 9
3 4 7 9
4 7 9
4
7 9
7
7 9

l.size()= 0

list数据访问，代码见下

#include
#include

using namespace std;

void printList(const list<int>& l) {
for (list<int>::const_iterator it = l.begin(); it != l.end(); it++) {
cout << *it << " ";
}
cout << endl;
}

int getListItemByIndex(list<int>& l, int index) {
list<int>::iterator it = l.begin();
while (index) {
it++;
index--;
}
return *it;
}

int main() {
list<int> l = { -1,
 2,
 1,
 3,
 4,
 7,
 9,
 -1 };

list<int>::iterator it = l.begin();
cout << getListItemByIndex(l, 4);
return 0;
}

list反转列表，代码见下，直接找的内部源码

void reverse() noexcept { // reverse sequence
const _Nodeptr _Phead = _Mypair._Myval2._Myhead;
_Nodeptr _Pnode = _Phead;

for (;;) { // flip pointers in a node
const _Nodeptr _Pnext = _Pnode->_Next;
_Pnode->_Next = _Pnode->_Prev;
_Pnode->_Prev = _Pnext;

if (_Pnext == _Phead) {
break;
}

_Pnode = _Pnext;
}
}

list数据排序，代码见下

#include
#include

using namespace std;

void printList(const list<int>& l) {
for (list<int>::const_iterator it = l.begin(); it != l.end(); it++) {
cout << *it << " ";
}
cout << endl;
}

int cmp(int a, int b) {
return a > b;
}

int main() {
list<int> l = { 2,
 1,
 3,
 4,
 7,
 9 };
printList(l);
l.sort(cmp);
printList(l);

return 0;
}