Question

Given a linked list, return the node where the cycle begins.

Answer 1

Answer:

ɢɪᴠᴇɴ ᴀ sɪɴɢʟʏ ʟɪɴᴋᴇᴅ ʟɪsᴛ, ғɪɴᴅ ᴍɪᴅᴅʟᴇ ᴏғ ᴛʜᴇ ʟɪɴᴋᴇᴅ ʟɪsᴛ. 

ғᴏʀ ᴇxᴀᴍᴘʟᴇ, ɪғ ɢɪᴠᴇɴ ʟɪɴᴋᴇᴅ ʟɪsᴛ ɪs 1->2->3->4->5 ᴛʜᴇɴ ᴏᴜᴛᴘᴜᴛ sʜᴏᴜʟᴅ ʙᴇ 3.

 ɪғ ᴛʜᴇʀᴇ ᴀʀᴇ ᴇᴠᴇɴ ɴᴏᴅᴇs, ᴛʜᴇɴ ᴛʜᴇʀᴇ ᴡᴏᴜʟᴅ ʙᴇ ᴛᴡᴏ ᴍɪᴅᴅʟᴇ ɴᴏᴅᴇs, ᴡᴇ ɴᴇᴇᴅ ᴛᴏ ᴘʀɪɴᴛ sᴇᴄᴏɴᴅ ᴍɪᴅᴅʟᴇ ᴇʟᴇᴍᴇɴᴛ. ғᴏʀ ᴇxᴀᴍᴘʟᴇ, ɪғ ɢɪᴠᴇɴ ʟɪɴᴋᴇᴅ ʟɪsᴛ ɪs 1->2->3->4->5->6 ᴛʜᴇɴ ᴏᴜᴛᴘᴜᴛ sʜᴏᴜʟᴅ ʙᴇ 4.