Submission #701489

#	Time	Username	Problem	Language	Result	Execution time	Memory
701489		PCTprobability	Fancy Fence (CEOI20_fancyfence)	C++17	30 / 100	6 ms	468 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 1000000007;
int main(){
  ll n;
  cin>>n;
  assert(n<=1000);
  vector<ll> a(n),b(n);
  for(int i=0;i<n;i++) cin>>a[i];
  for(int i=0;i<n;i++) cin>>b[i];
  ll ans=0;
  for(int i=0;i<n;i++) (ans+=((b[i]*(b[i]+1))/2%mod)*((a[i]*(a[i]+1)/2)%mod))%=mod;
  ans%=mod;
  for(int i=0;i<n;i++){
    ll x=a[i];
    for(int j=i+1;j<n;j++){
      x=min(x,a[j]);
      ans+=(x*(x+1)/2%mod)*b[i]%mod*b[j]%mod;
      ans%=mod;
    }
  }
  cout<<ans<<endl;
}

• Subtask 1: 0 / 0
• Subtask 2: 12 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 18 / 18
• Subtask 7: 0 / 27