【UOJ】#273. 【清华集训2016】你的生命已如风中残烛

题目链接：http://uoj.ac/problem/273

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$${Ans=\frac{\prod _{i=1}^{m}i}{w-n+1}}$$

 #include<iostream>
 #include<cstdio>
 #include<algorithm>
 #include<vector>
 #include<cstdlib>
 #include<cmath>
 #include<cstring>
 using namespace std;
 #define maxn 10010
 #define llg int
 #define md 998244353
 #define yyj(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);
 llg n,m,ans,x,w;

 inline int getint()
 {
     int w=;
     char c=getchar();
     while((c<'' || c>'') && c!='-') c=getchar();
     //if (c=='-')  q=1, c=getchar();
     while (c>='' && c<='') w=w*+c-'', c=getchar();
     return w;
 }

 int main()
 {
     yyj("a");
     cin>>n;
     for (register llg i=;i<=n;i++)
     {
         x=getint();
         w+=x;
     }
     ans=;
     for (register llg i=;i<=w;i++)  if (i+n!=w+) ans=1LL*ans*i%md;
     cout<<ans;
     return ;
 }