leetcode-234 - Palindrome Linked List

動機 可以去看143 重點是找中點時判斷長度的奇偶姓!! ...

July 23, 2021 · 1 min · zhengcf

leetcode-240 - Search a 2D Matrix II

動機 複習saddle back ...

July 23, 2021 · 1 min · zhengcf

leetcode-279 - Perfect Squares

動機 複習換硬幣的dp isqrt是個很貴的運算 ...

July 23, 2021 · 1 min · zhengcf

leetcode-287 - Find the Duplicate Number

動機 這題有很多有趣的解法 ...

July 23, 2021 · 2 min · zhengcf

leetcode-34 - Find First and Last Position of Element in Sorted Array

動機 lowerbound與upperbound只差一個等號!! ...

July 22, 2021 · 1 min · zhengcf

leetcode-17 - Letter Combinations of a Phone Number

動機 複習backtrack ...

July 22, 2021 · 1 min · zhengcf

leetcode-136 - Single Number

動機 XOR!! ...

July 22, 2021 · 1 min · zhengcf

leetcode-138 - Copy List with Random Pointer

動機 這種copy有ptr的都要另外存新複製的node ...

July 22, 2021 · 2 min · zhengcf

leetcode-417 - Pacific Atlantic Water Flow

動機 要用dfs(+dp)要注意會不會重複走 ...

July 22, 2021 · 2 min · zhengcf

leetcode-424 - Longest Repeating Character Replacement

動機 lee215太神啦!! ...

July 22, 2021 · 2 min · zhengcf