# Definition for singly-linked list.
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution:
def hasCycle(self, head: ListNode) -> bool:
ptr1 = head
ptr2 = head
if not ptr2:
return False
if not ptr2.next:
return False
while ptr2.next :
ptr1 = ptr1.next
ptr2 = ptr2.next
if not ptr2.next:
return False
ptr2 = ptr2.next
if ptr1 == ptr2:
return True
return False50. Pow(x, n) | 43. Multiply Strings |
34. Find First and Last Position of Element in Sorted Array | 33. Search in Rotated Sorted Array |
17. Letter Combinations of a Phone Number | 5. Longest Palindromic Substring |
3. Longest Substring Without Repeating Characters | 1312. Minimum Insertion Steps to Make a String Palindrome |
1092. Shortest Common Supersequence | 1044. Longest Duplicate Substring |
1032. Stream of Characters | 987. Vertical Order Traversal of a Binary Tree |
952. Largest Component Size by Common Factor | 212. Word Search II |
174. Dungeon Game | 127. Word Ladder |
123. Best Time to Buy and Sell Stock III | 85. Maximal Rectangle |
84. Largest Rectangle in Histogram | 60. Permutation Sequence |
42. Trapping Rain Water | 32. Longest Valid Parentheses |
Cutting a material | Bubble Sort |
Number of triangles | AND path in a binary tree |
Factorial equations | Removal of vertices |
Happy segments | Cyclic shifts |