摘要：【题目】 若干个数字间，使用加法或减法连接，最终得到目标和target，求所有满足条件解的个数 You are given an integer array nums and an integer target. You want to build an expression out of nums 阅读全文

摘要：【题目】 Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination shoul 阅读全文

摘要：【题目】 There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the followi 阅读全文