摘要：
Given the root of a binary tree, each node has a value from 0 to 25 representing the letters 'a' to 'z': a value of 0 represents 'a', a value of 1 rep 阅读全文
摘要：
This problem was asked by Google. On our special chessboard, two bishops attack each other if they share the same diagonal. This includes bishops that 阅读全文