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https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
39 lines
744 B
C++
39 lines
744 B
C++
#include <iostream>
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#include <string.h>
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#include <stdio.h>
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using namespace std;
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typedef long long LL;
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const int N=2005;
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const LL MOD=1000000007;
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LL C[N][N];
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LL S[N][N];
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void Init()
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{
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int i,j;
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for(i=0;i<N;i++)
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{
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C[i][0]=1;
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C[i][i]=1;
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S[i][0]=0;
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S[i][i]=1;
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for(j=1;j<i;j++)
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{
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C[i][j]=(C[i-1][j]%MOD+C[i-1][j-1]%MOD)%MOD;
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S[i][j]=((i-1)%MOD*S[i-1][j]%MOD+S[i-1][j-1]%MOD);
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}
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}
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}
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int main()
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{
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LL t,n,f,b,ans;
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Init();
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scanf("%I64d",&t);
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while(t--)
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{
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scanf("%I64d%I64d%I64d",&n,&f,&b);
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ans=C[f+b-2][f-1]%MOD*S[n-1][f+b-2]%MOD;
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printf("%I64d\n",ans);
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}
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return 0;
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}
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