HDU 4945 2048


Time Limit: 3000/1500 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 590 Accepted Submission(s): 136

Problem Description

Teacher Mai is addicted to game 2048. But finally he finds it’s too hard to get 2048. So he wants to change the rule:

You are given some numbers. Every time you can choose two numbers of the same value from them and merge these two numbers into their sum. And these two numbers disappear meanwhile.

If we can get 2048 from a set of numbers with this operation, Teacher Mai think this multiset is good.

You have n numbers, A1,…,An. Teacher Mai ask you how many subsequences of A are good.

The number can be very large, just output the number modulo 998244353.