#include<bits/stdc++.h>
//#include "grader.h"
#define pii pair<int, int>
#define pll pair<long long, long long>
#define ll long long
#define ld long double
#define st first
#define nd second
#define pb push_back
#define INF INT_MAX
using namespace std;
const int N = 1e5 + 10;
const int M = 1e9+7;
stack<int> s;
ll h[N], w[N], qs[N];
ll power(ll a, ll b) {
if (b == 0) return 1;
ll ret = power(a, b/2);
if (b&1) return ret*ret%M*a%M;
else return ret*ret%M;
}
void solve() {
int n; cin >> n;
for (int i = 1; i <= n; ++i) cin >> h[i];
for (int i = 1; i <= n; ++i) cin >> w[i], qs[i] = qs[i-1]+w[i];
ll ans = 0;
ll inv = power(2, M-2);
s.push(0);
for (int i = 1; i <= n; ++i) {
while (h[s.top()] > h[i]) {
ll H = h[s.top()];
H %= M;
ll W = qs[i-1] - qs[s.top()-1];
W %= M;
s.pop();
H -= max(h[s.top()], h[i]);
ans += ((H)*(H+1)%M*inv%M * (W*(W+1)%M*inv)%M)%M;
ans %= M;
ans += (H*h[s.top()]%M * (W*(W+1)%M*inv)%M)%M;
ans %= M;
}
s.push(i);
}
while (s.size() > 1) {
ll H = h[s.top()];
H %= M;
ll W = qs[n] - qs[s.top()-1];
W %= M;
s.pop();
H -= h[s.top()];
ans += ((H)*(H+1)%M*inv%M * (W*(W+1)%M*inv)%M)%M;
ans %= M;
ans += (H*h[s.top()]%M * (W*(W+1)%M*inv)%M)%M;
ans %= M;
}
cout << ans << '\n';
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
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 |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
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 |
- |