mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
61 lines
1.2 KiB
C++
61 lines
1.2 KiB
C++
#include<iostream>
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#include<cstdio>
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#include<cstring>
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#include<string>
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#include<algorithm>
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#include<map>
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#include<queue>
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#include<stack>
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#include<cmath>
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#include<vector>
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#define inf 0x3f3f3f3f
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#define Inf 0x3FFFFFFFFFFFFFFFLL
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#define eps 1e-9
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#define pi acos(-1.0)
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using namespace std;
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typedef long long ll;
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const int maxn=365;
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const int mod=1000000000+7;
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ll dp[maxn][maxn],C[maxn][maxn];
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void Init()
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{
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memset(C,0,sizeof(C));
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C[0][0]=1;
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for(int i=1;i<maxn;++i)
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{
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C[i][0]=1;
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for(int j=1;j<=i;++j)
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{
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C[i][j]=C[i-1][j-1]+C[i-1][j];
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if(C[i][j]>=mod) C[i][j]-=mod;
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}
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}
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}
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ll f(int n,int d)
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{
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if(n==1&&d>=1) return 1;
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if(n==1||d==0) return 0;
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if(dp[n][d]!=-1) return dp[n][d];
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ll &ans=dp[n][d];
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ans=0;
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ans=(ans+f(n-1,d-1)*n*2)%mod;
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for(int k=1;k<=n-2;++k)
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ans=(ans+(f(k,d-1)*f(n-k-1,d-1)%mod*C[n-2][k]%mod)*n)%mod;
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return ans;
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}
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int main()
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{
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Init();
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memset(dp,0xff,sizeof(dp));
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int t,tcase=0,n,d;
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scanf("%d",&t);
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while(t--)
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{
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scanf("%d%d",&n,&d);
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ll ans=f(n,d)-f(n,d-1);
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ans=(ans+mod)%mod;
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printf("Case #%d: %I64d\n",++tcase,ans);
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}
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return 0;
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}
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