Count and SayThe count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, … 1 is read off as “one 1” or 11. 11 is read off as “two 1s” or 21. 21 is read off a
Valid SudokuThe Sudoku board could be partially filled, where empty cells are filled with the character ‘.’. Note: A valid Sudoku board (partially filled) is not necessarily solvable. Only the fille
Remove ElementGiven an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you must do this in place with constant
Remove Duplicates from Sorted ArrayGiven a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another arra
Swap Nodes in PairsGiven a linked list, swap every two adjacent nodes and return its head. For example: 1Given 1->2->3->4, you should return the list as 2->1->4->3. Your algorithm s
Merge Two Sorted ListsMerge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 提示 解題應用 LinkedList Pointer
Valid ParenthesesGiven a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[‘ and ‘]’, determine if the input string is valid. The brackets must close in the correct order, “()” and “()[]{}”
Remove Nth Node From End of ListGiven a linked list, remove the nth node from the end of list and return its head. Example: 123Given linked list: 1->2->3->4->5, and n = 2.After removing t
Longest Common PrefixWrite a function to find the longest common prefix string amongst an array of strings. 提示 解題應用 String Prefix String Default:123func longestCommonPrefix(strs []string) s
Roman to IntegerGiven a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 提示 解題應用 Math 規律觀察 String 規律觀察 Default:12func romanToInt(s strin
Reverse IntegerReverse digits of an integer. Exmaple1:1x = 123, return 321 Exmaple2:1x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points
Palindrome NumberDetermine whether an integer is a palindrome. Do this without extra space. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer
ZigZag ConversionThe string “PAYPALISHIRING” is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) Exmaple:1