题目大意 给定长度为m和n的两个数组，数组里面数字为0到9.要求从这两个数组里面去k个数字构成的数字的最大值。k<=m+n。题目要求新的数字的顺序跟原来数组的数字顺序保持一致。

题目大意 给定一堆硬币和一个数字，求组成那个数字的最少硬币个数。如果币值没法构成给定数字，返回 -1

题目大意 给定一个整型数组，里面没有重复数字。求解所有可能的组合使得组合的和为给定的整数。

题目大意 给定一个数组，求能不能把数组分成两部分使得两个子数组的和相等

It is important that credit card companies are able to recognize fraudulent credit card transactions so that customers are not charged for items that they did not purchase. This dataset presents transactions that occurred in two days, where we have 492 frauds out of 284,807 transactions. The dataset is highly unbalanced.

It is important that credit card companies are able to recognize fraudulent credit card transactions so that customers are not charged for items that they did not purchase. This dataset presents transactions that occurred in two days, where we have 492 frauds out of 284,807 transactions. The dataset is highly unbalanced.

It is important that credit card companies are able to recognize fraudulent credit card transactions so that customers are not charged for items that they did not purchase. This dataset presents transactions that occurred in two days, where we have 492 frauds out of 284,807 transactions. The dataset is highly unbalanced.

题目大意，给定一个数学表达式，在表达式的不同地方添加括号来表示不同的运算顺序，求最后有多少种不同的运算结果

题目大意，给定一个无序的数列，求这个序列的最长单调增的子序列的长度。

这是一道easy的题目，但是有很多变种