滴滴数据相关面试真题

给一个整数N，返回一个string.

string中只能包含小写字母，每个字母只能出现奇数次

Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.

The same number may be chosen from candidates an unlimited number of times. Two combinations are unique if the

frequency of at least one of the chosen numbers is different.

The test cases are generated such that the number of unique combinations that sum up to target is less than 150 combinations for the given input.

随机森林和GradientBoostTree的区别，如何调参。

如何防止过度拟合

滴滴一月份从surge price变成了排队先到先得，分析优劣势，排队时会积攒需求，怎样消化这部分需求。