Navicat连接MySQL Server8.0版本时出现Client does not support authentication protocol requested by server；解决如下：
命令如下：
1、use mysql;
2、alter user 'root'@'localhost' identified with mysql_native_password by '********';
3、flush privileges;
全排列问题
56. Merge Interval
2. Add Two Numbers
20. Valid Parentheses
121. Best Time to Buy and Sell Stock
120. Triangle
96. Unique Binary Search Trees
91. Decode Ways
72. Edit Distance