Gym - 101810E ACM International Collegiate Programming Contest (2018)

bryce1010模板

 http://codeforces.com/gym/101810

#include<bits/stdc++.h>

using namespace std;

#define ll long long 

const ll maxn = 1e5 + 5;

const ll mod = 1e9+7;

ll n;

ll p[maxn];

ll vis[maxn];

int main()

{

    ll t;

    scanf("%lld",&t);

    ll pre;

    while(t--)

    {

        scanf("%lld",&n);

        pre = 1;

        for(int i=1;i<=n;i++)

        {

            scanf("%lld",&p[i]);

        }

        fill(vis,vis+1+n,1);

        for(int i=1;i<=n;i++)

        {

            vis[i] = pre*vis[i]%mod;

            pre = p[i]*pre%mod;

        }

        vis[0] = n*pre%mod;

        pre = 1;

        for(int i=n;i>=1;i--)

        {

            vis[i] = pre*vis[i]%mod;

            pre = p[i]*pre%mod;

        }

        ll ans = vis[0];

        for(int i=1;i<=n;i++)

        {

            ans = (mod+ans-vis[i])%mod;

        }

        printf("%lld\n",ans);

    }

    return 0;

}

巴特西

Gym - 101810E ACM International Collegiate Programming Contest (2018)

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