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
leetcode 377. Combination Sum IV
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。
leetcode 416. Partition Equal Subset Sum
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
Credit Card Fraud Detection / Imbalanced data modeling - Part III: Ensembling/Stacking models
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.
Credit Card Fraud Detection / Imbalanced data modeling - Part II: Random Forest
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.
Credit Card Fraud Detection / Imbalanced data modeling - Part I: Logistic Regression
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.
241. Different Ways to Add Parentheses
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
300. Longest Increasing Subsequence
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。
leetcode 303. Range Sum Query - Immutable
这是一道easy的题目，但是有很多变种
leetcode 304. Range Sum Query 2D - Immutable
题目大意，给定一个二维矩阵，再给定左上角和右下角的坐标，求坐标围成的矩形的元素的和