https://blog.youkuaiyun.com/qq276592716/article/details/7932483
list不能使用STL算法sort(),必须使用自己的sort()member functiion,因为STL算法sort()只接受Ramdon Access Iterator.
template <class _Tp, class _Alloc>
void list<_Tp, _Alloc>::sort()
{
// Do nothing if the list has length 0 or 1.
if (_M_node->_M_next != _M_node && _M_node->_M_next->_M_next != _M_node) {
list<_Tp, _Alloc> __carry;
list<_Tp, _Alloc> __counter[64];
int __fill = 0;
while (!empty()) {
__carry.splice(__carry.begin(), *this, begin());
int __i = 0;
while(__i < __fill && !__counter[__i].empty()) {
__counter[__i].merge(__carry);
__carry.swap(__counter[__i++]);
}
__carry.swap(__counter[__i]);
if (__i == __fill) ++__fill;
}
for (int __i = 1; __i < __fill; ++__i)
__counter[__i].merge(__counter[__i-1]);
swap(__counter[__fill-1]);
}
}