AT_ttpc2024_2_k 01 Abs Sum

Description

You are given a sequence $ A = (A_1, A_2, \cdots, A_N) $ of length $ N $ , consisting of $ 0 $ , $ 1 $ , and $ -1 $ . There are $ 2^q $ ways to replace all $ -1 $ s in $ A $ with either $ 0 $ or $ 1 $ , where $ q $ is the number of $ -1 $ s in $ A $ . Among these, for all sequences that contain both $ 0 $ and $ 1 $ , calculate the sum of the answers to the following problem modulo $ 998244353 $ : > Let $ \alpha $ and $ \beta $ be the number of $ 0 $ s and $ 1 $ s in $ A $ , respectively. > Also, let $ X = (X_0, X_1, \cdots, X_{\alpha-1}) $ be the sequence of indices of $ A_i = 0 $ , arranged in increasing order, and let $ Y = (Y_0, Y_1, \cdots, Y_{\beta-1}) $ be the sequence of indices of $ A_i = 1 $ , arranged in increasing order (note that the indices of $ X $ and $ Y $ start from $ 0 $ ). > > $ \displaystyle\sum_{i=0}^{\mathrm{LCM}(\alpha, \beta)-1} |X_{(i \bmod \alpha)} - Y_{(i \bmod \beta)}| $ > > > > Calculate the value of the above expression. Here, $ \mathrm{LCM}(x, y) $ represents the least common multiple of $ x $ and $ y $ , and $ x \bmod y $ denotes the remainder when $ x $ is divided by $ y $ .

Input Format

The input is given in the following format: > $ N $ $ A_1 $ $ A_2 $ $ \cdots $ $ A_N $

Output Format

Output the answer.

Explanation/Hint

### Partial Score - $ 30 $ points will be awarded for passing the test set satisfying the additional constraint $ N \leq 100 $ . ### Sample Explanation 1 For $ A = (1, 1, 0, 0) $ , $ |3 - 1| + |4 - 2| = 4 $ . For $ A = (1, 1, 0, 1) $ , $ |3 - 1| + |3 - 2| + |3 - 4| = 4 $ . For $ A = (1, 1, 1, 0) $ , $ |4 - 1| + |4 - 2| + |4 - 3| = 6 $ . Thus, the answer is $ 4 + 4 + 6 = 14 $ . ### Sample Explanation 2 Since it is not possible to form a sequence containing both $ 0 $ and $ 1 $ , the answer is $ 0 $ . ### Constraints - All input values are integers. - $ 2 \leq N \leq 2250 $ - Each $ A_i $ is either $ 0 $ , $ 1 $ , or $ -1 $ $ (i = 1, 2, \cdots, N) $ .