c++ - 在列表中向下移动一个元素 C++

Question

我需要一些帮助，我需要能够在链表中找到一个元素并将其在链表中向下移动。我该怎么做？

例子: 1 2 3 4

找到2并切换到下一个

输出:1 3 2 4

向下移动 2 两个空格2 3 4 1

Answer 1

如果您正在使用 std::list，这就相当简单了。首先，搜索您的电话号码，得到一个指向列表中该位置的迭代器。例如:

std::list<int> mylist;

//populate your list with the digits you want

//find the element in the list
int element = 5;
std::list<int>::iterator current = mylist.begin();
for (; current != mylist.end(); current++)
{
    if (*current == element)
        break;
}

//Now move your element two positions back (let's assume you have the elements in
//the list to-do that amount of movement, but nevertheless,
//we still check the list bounds and exit the loop if we hit the front of the list)
for (std::list<int>::iterator new_position = current, int i=0; 
     (i < 2 && new_position != mylist.begin()); 
     i++, new_position--);

mylist.insert(new_position, 1, *current);

//erase where the element used to be
mylist.erase(current);

如果您不使用 std::list，请使用 std::list :-)