Created
December 8, 2016 04:44
-
-
Save reddragon/3e92905af4e6a51d4415be64a4567b13 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <iostream> | |
#include <cassert> | |
#include <set> | |
#include <map> | |
#include <vector> | |
#include <algorithm> | |
#include <utility> | |
#include <cstdio> | |
#include <limits> | |
#include <bitset> | |
#include <string> | |
#include <iterator> | |
#include <cmath> | |
#include <queue> | |
#include <numeric> | |
using namespace std; | |
struct ListNode { | |
int val; | |
ListNode *next; | |
ListNode(int x) : val(x), next(NULL) {} | |
void setNext(ListNode *n) { next = n; } | |
}; | |
class Solution { | |
public: | |
ListNode* hasCycleNode(ListNode *h) { | |
auto s = h; | |
auto f = h; | |
int iter = 0; | |
while (s != nullptr && f != nullptr) { | |
if (iter > 0 && s == f) return s; | |
s = s->next; | |
f = (f->next != nullptr ? f->next->next : nullptr); | |
iter++; | |
} | |
return nullptr; | |
} | |
bool hasCycle(ListNode *h) { | |
return hasCycleNode(h) != nullptr; | |
} | |
}; | |
#define DECL_NODES \ | |
ListNode *n1 = new ListNode(1); \ | |
ListNode *n2 = new ListNode(2); \ | |
ListNode *n3 = new ListNode(3); \ | |
ListNode *n4 = new ListNode(4); \ | |
ListNode *n5 = new ListNode(5); \ | |
ListNode *n6 = new ListNode(6) | |
void setUpNext(vector<ListNode*> v) { | |
for (int i = 0; i < v.size(); i++) { | |
if (i+1 < v.size()) v[i]->setNext(v[i+1]); | |
} | |
} | |
int main() { | |
Solution s; | |
{ | |
DECL_NODES; | |
setUpNext({n1, n2, n3, n4, n5, n6}); | |
assert(s.hasCycle(n1) == false); | |
} | |
{ | |
DECL_NODES; | |
setUpNext({n1, n2, n3, n4, n5, n6, n2}); | |
assert(s.hasCycle(n1) == true); | |
} | |
{ | |
DECL_NODES; | |
setUpNext({n1, n2, n3, n4, n5, n6, n6}); | |
assert(s.hasCycle(n1) == true); | |
} | |
{ | |
DECL_NODES; | |
setUpNext({n1, n2, n3, n4, n5, n6, n3}); | |
assert(s.hasCycle(n1) == true); | |
} | |
{ | |
DECL_NODES; | |
setUpNext({n1, n2, n3, n4, n5, n6, n1}); | |
assert(s.hasCycle(n1) == true); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment