#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
//~ #define ll int
#define int ll
typedef pair<int32_t, int32_t> pi;
typedef vector <int> vi;
typedef vector <pi> vpi;
typedef pair<pi, ll> pii;
typedef set <ll> si;
typedef long double ld;
#define f first
#define s second
#define mp make_pair
#define FOR(i,s,e) for(int i=s;i<=int(e);++i)
#define DEC(i,s,e) for(int i=s;i>=int(e);--i)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lbd(x, y) lower_bound(all(x), y)
#define ubd(x, y) upper_bound(all(x), y)
#define aFOR(i,x) for (auto i: x)
#define mem(x,i) memset(x,i,sizeof x)
#define fast ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define maxn 200001
#define INF 1e9
#define MOD 1000000007
typedef pair <vi, int> pvi;
typedef pair <int,pi> ipi;
typedef vector <pii> vpii;
int N,H[maxn],W[maxn],ss[maxn],ss2[maxn];
int32_t main(){
fast;
cin >> N;
FOR(i,1,N) cin >> H[i];
FOR(i,1,N) cin >> W[i];
FOR(i,1,N){
ss[i] = (ss[i-1] + W[i]) % MOD;
ss2[i] = (ss2[i-1] + (W[i] * W[i]) % MOD) % MOD;
}
set <int> st;
vi v(N); iota(all(v), 1);
sort(all(v), [](int i,int j){
return H[i] < H[j];
});
int ans = 0;
st.insert(N+1); st.insert(0);
aFOR(i,v){
int l = *(--st.lower_bound(i)) + 1;
int r = *st.upper_bound(i) - 1;
int res = 0;
(res += ((ss[r] - ss[l-1]) * (ss[r] - ss[l-1])) % MOD) %= MOD;
(res -= (ss2[r] - ss2[l-1]) % MOD) %= MOD;
(res -= ((ss[r] - ss[i]) * (ss[r] - ss[i])) % MOD) %= MOD;
(res += (ss2[r] - ss2[i]) % MOD) %= MOD;
(res -= ((ss[i-1] - ss[l-1]) * (ss[i-1] - ss[l-1])) % MOD) %= MOD;
(res += (ss2[i-1] - ss2[l-1]) % MOD) %= MOD;
res /= 2;
//~ (res -= (W[i] * W[i]) % MOD) %= MOD;
int hc2 = (H[i] * (H[i] + 1) / 2) % MOD;
(ans += (res * hc2) % MOD) %= MOD;
//~ cout << ans << '\n';
st.insert(i);
}
FOR(i,1,N){
(ans += ((((W[i] * (W[i]+1)) / 2) % MOD)
* (((H[i] * (H[i]+1)) / 2) % MOD)) % MOD) %= MOD;
}
if (ans < 0) ans += MOD;
cout << ans;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
340 KB |
Output is correct |
2 |
Incorrect |
1 ms |
400 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
0 ms |
340 KB |
Output is correct |
5 |
Correct |
0 ms |
340 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
340 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
340 KB |
Output is correct |
2 |
Incorrect |
1 ms |
400 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |