58 lines
1.2 KiB
C++
58 lines
1.2 KiB
C++
#include <iostream>
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#include <cstdio>
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#include <cstdlib>
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#include <cstring>
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#include <cmath>
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#include <algorithm>
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#include <string>
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#include <vector>
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#include <stack>
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#include <queue>
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#include <set>
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#include <time.h>
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using namespace std;
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const int MOD = 1e9+7;
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long long inv(long long a,long long m)
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{
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if(a == 1)return 1;
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return inv(m%a,m)*(m-m/a)%m;
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}
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const int MAXN = 1000010;
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int a[MAXN];
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int main()
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{
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int T;
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int n;
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scanf("%d",&T);
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while(T--)
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{
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scanf("%d",&n);
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long long S = 1;
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for(int i = 0;i < n;i++)
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{
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scanf("%d",&a[i]);
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S *= a[i];
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S %=MOD;
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}
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long long ans = S*n%MOD;
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sort(a,a+n);
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reverse(a,a+n);
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int cnt = n-1;
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for(int i = 0;i < n;i++)
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{
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if(cnt == 0)break;
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long long tmp = S*inv(a[i],MOD)%MOD;
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ans -= tmp;
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ans = (ans%MOD+MOD)%MOD;
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cnt--;
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if(cnt == 0)break;
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ans -= tmp;
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ans = (ans%MOD+MOD)%MOD;
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cnt--;
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if(cnt == 0)break;
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}
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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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