摘要：
Given an array A of 0s and 1s, divide the array into 3 non-empty parts such that all of these parts represent the same binary value. If it is possible 阅读全文
摘要：
Given an array A of integers, for each integer A[i] we need to choose either x = -K or x = K, and add x to A[i] (only once). After this process, we ha 阅读全文
摘要：
Given a string S of '(' and ')' parentheses, we add the minimum number of parentheses ( '(' or ')', and in any positions ) so that the resulting paren 阅读全文