Submission #745851

#	Time	Username	Problem	Language	Result	Execution time	Memory
745851		vjudge1	Fancy Fence (CEOI20_fancyfence)	C++17	30 / 100	27 ms	3916 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod = 1e9 + 7;

ll solve_rect(ll h, ll w) {
  h %= mod;
  w %= mod;
  ll hc = (h * (h + 1) / 2) % mod;
  ll wc = (w * (w + 1) / 2) % mod;
  return (hc * wc) % mod;
}

int main() {
  ios::sync_with_stdio(0), cin.tie(0);
  int n;
  cin >> n;
  vector<ll> hv(n), wv(n);
  for (ll& h : hv) cin >> h;
  ll w_rem = 0;
  for (ll& w : wv) {
    cin >> w;
    w_rem += w;
    w_rem %= mod;
  }
  ll res = 0ll;
  ll h_prev = 0ll;
  for (int i = 0; i < n; i++) {
    int h = hv[i], w = wv[i];
    res += solve_rect(h, w_rem);
    res %= mod;
    res -= solve_rect(h_prev, w_rem);
    res += mod;
    res %= mod;
    w_rem += mod;
    w_rem -= w;
    h_prev = h;
  }
  cout << res;
}

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