5492: K-Yiwen with Formula
内存限制：128 MB
时间限制：60.000 S
评测方式：文本比较
命题人：
提交：12
解决：2
题目描述
Given an array a of length n, for any array b satisfying 1≤bi≤n and b1<b2<⋯<bk (k is the length of b, k≥1), calculate:
输入
The input consists of multiple test cases.
The first line contains an integer T (1≤T≤10) -- the number of test cases.
For each test case:
The first line contains an integer n (1≤n≤10^5), which is the length of a.
The second line contains n integers ai (0≤ai≤10^5), which is the array a.
It is guaranteed that:
- The sum of n over all test cases will not exceed 2.5×10^5.
- The sum of ai in a single test will not exceed 10^5.
- The sum of ai over all test cases will not exceed 4×10^5.
The first line contains an integer T (1≤T≤10) -- the number of test cases.
For each test case:
The first line contains an integer n (1≤n≤10^5), which is the length of a.
The second line contains n integers ai (0≤ai≤10^5), which is the array a.
It is guaranteed that:
- The sum of n over all test cases will not exceed 2.5×10^5.
- The sum of ai in a single test will not exceed 10^5.
- The sum of ai over all test cases will not exceed 4×10^5.
输出
For each test case, output the result modulo 998244353 in a single line.
样例输入 复制
3
2
1 1
3
1 1 2
5
4 6 9 1 5样例输出 复制
2
144
417630946