5330: Sample Game
内存限制:512 MB
时间限制:2.000 S
评测方式:文本比较
命题人:
提交:0
解决:0
题目描述
Bob has a random number generator, it will generate x with probability px.
Now Bob will do the following operations:
If the answer is irreducible fraction x/y, you need to output an integer d in [0,998244352] which satisfies d * y mod 998244353=x mod 998244353.
It's guaranteed that y mod 998244353≠0.
Now Bob will do the following operations:
- Step 1. Generate a number x by random number generator.
- Step 2. If x is the largest number among the generated numbers (i.e. x is no smaller than any previously generated numbers), go to step 1, otherwise, go to step 3.
- Step 3. If Bob generates x numbers totally, Bob will get x2 score.
If the answer is irreducible fraction x/y, you need to output an integer d in [0,998244352] which satisfies d * y mod 998244353=x mod 998244353.
It's guaranteed that y mod 998244353≠0.
输入
The first line has one integers n, it means the random number generator can only generate integers in [1,n].
The second line has n positive integers w1...n, it means pi = wi /(∑j=1n wj).
2≤n≤100,1≤wi≤106.
The second line has n positive integers w1...n, it means pi = wi /(∑j=1n wj).
2≤n≤100,1≤wi≤106.
输出
Output the answer.
样例输入 复制
3
1 1 1
样例输出 复制
499122190