摘要：
首先上题目：A DNA sequence can be represented as a string consisting of the letters A, C, G and T, which correspond to the types of successive nucleotides i... 阅读全文
摘要：
A non-empty zero-indexed array A consisting of N integers is given. A pair of integers (P, Q), such that 0 ≤ P < Q < N, is called a slice of array A (notice that the slice contains at least two elemen... 阅读全文
摘要：
No need for a double cycle: :You are given N counters, initially set to 0, and you have two possible operations on them:increase(X) − counter X is inc... 阅读全文