职场小白开始认真刷题

开刷leetcode 现在准备每天3道题
求监督
求一起的刷题

171.        Excel Sheet Column Number
1512. Number of good Pairs
2. Add Two Numbers

53.        Maximum Subarray   
101.        Symmetric Tree
200.        Number of Islands

437.         Path Sum III
309.        Best Time to Buy and Sell Stock with Cooldown
17.        Letter Combinations of a Phone Number
DFS 还是不熟练，没有这个直觉和这个algo的套路，需加强联系

56.        Merge Intervals
617.        Merge Two Binary Trees
21.        Merge Two Sorted Lists