摘要： Suppose n is the number of list, then the runtime is O(n^2/2), space is O(n) We create an integer array of size n, which is also the number of digits 阅读全文

摘要： In this problem, we cannot find an efficient recursion way to set up the next pointer. For example, we can do like this, in this way we may set up too 阅读全文