How to find whether a linked list is a circular linked list

[jblackwood3]

I know that I am digging up an old post, but would this also work?

bool circleFound(Node* headNode)
{
bool circleFound = false;
hash_map <Node*,int> hashedNodes;
Node * currNode = headNode;

while(currNode)
{
if (hashedNodes[currNode] > 0)
{
circleFound = true;
break;
}
hashedNodes[currNode] = 1;
currNode = currNode->next;
}
return circleFound;
}