摘要：
There are N piles of stones arranged in a row. The i-th pile has stones[i] stones. A move consists of merging exactly K consecutive piles into one pil 阅读全文
摘要：
Given an array A of 0s and 1s, we may change up to K values from 0 to 1. Return the length of the longest (contiguous) subarray that contains only 1s. 阅读全文
摘要：
We are given that the string "abc" is valid. From any valid string V, we may split V into two pieces X and Y such that X + Y (X concatenated with Y) i 阅读全文