878 Middle of the linked list
- Based on the concept of cycle finding in linked list
- If there is no cycle, then by the time faster one reached to the end, slower one should be at
half the distance.
- because rate of faster one was doubled.
Code
```cpp
ListNode* middleNode(ListNode* head) {
auto s = head;
auto f = head;
while (f and f -> next) {
s = s -> next;
f = f -> next -> next;
}
return s;
}
```