P22301 [CodeChef] SUMOFCUBE
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题目描述

You are given an array A consisting of N positive integers.

Find $\sum_{i=1}^{N} \sum_{j=i}^{N} F^{3}(i,j)$, where $F(i,j)=\sum_{k=i}^{j} A_{k}$.

Since the value might be quite large, print it modulo 998244353.

------ Input Format ------

  • The first line of input contains a single integer T, denoting the number of test cases.
  • Each test case consists of two lines of input.
  • The first line of each test case contains an integer N — the length of the array A.
  • The second line of each test case contains $N space-separated integers A_{1},A_{2},\ldots,A_{N}$ representing the array A.

------ Output Format ------

For each test case, output on a new line, the answer, modulo 998244353.

------ Constraints ------

$1 ≤ T ≤ 10^{5}$
$1 ≤ N ≤ 5 \cdot 10^{5}$
$1 ≤ A_{i} ≤ 10^{6}$
- The sum of $N$ over all test cases won't exceed $5 \cdot 10^{5}$.

----- Sample Input 1 ------
3
2
1 1
3
1 2 1
5
8 5 6 2 3

----- Sample Output 1 ------
10
128
42621
----- explanation 1 ------
Test case $1$: $F(1, 1) = 1, F(1, 2) = 1+1=2, F(2, 2) = 1$.

Thus, $\sum_{i=1}^{N} \sum_{j=i}^{N} F^{3}(i,j) = 1^{3} + 2^{3} + 1^{3} = 10$.

Test case $2$: $F(1, 1) = 1, F(1, 2) = 1+2=3, F(1, 3) = 1+2+1 =4, F(2, 2) = 2, F(2, 3) = 2+1=3, F(3, 3) = 1$.

Thus, $\sum_{i=1}^{N} \sum_{j=i}^{N} F^{3}(i,j) = 1^{3} + 3^{3} + 4^{3}+2^{3}+3^{3}+1^{3} = 128$.

输入格式

见题面

输出格式

见题面

样例输入
3 2 1 1 3 1 2 1 5 8 5 6 2 3
样例输出
10 128 42621