#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll tab[1000005];
ll h[1000005];
ll w[1000005];
ll dp[1000005];
ll mod = 1e9+7;
ll notdp[1000005];
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int n;
cin >> n;
for(int i = 1; i <= n; i++)
{
cin >> h[i];
}
for(int i = 1; i <= n; i++)
{
cin >> w[i];
}
dp[1] = ((((h[1] * (h[1]+1))%mod)/2) * w[1]) % mod;
vector<pair<ll, ll>> v;
v.push_back({0, 0});
v.push_back({h[1], 1});
for(int i = 2; i <= n; i++)
{
ll temp = w[i];
notdp[i] = ((((h[i] * (h[i]+1))%mod)/2) * ((w[i] * (w[i]+1))%mod)/2 ) % mod;
notdp[i] = (notdp[i] - (((h[i] * (h[i]+1))%mod)/2 * w[i])%mod + mod) % mod;
while(v.back().first > h[i])
{
w[i] += w[v.back().second];
v.pop_back();
}
ll inbig = ((((h[i] * (h[i]+1))%mod)/2) * ((w[i] * (w[i]+1))%mod)/2 ) % mod;
inbig = (inbig - (((h[i] * (h[i]+1))%mod)/2 * w[i]) % mod + mod) % mod;
inbig = (inbig - notdp[i] + mod) % mod;
notdp[i] = (notdp[i] + inbig) % mod;
ll fromdp = (dp[v.back().second] * temp) % mod;
fromdp = (fromdp - dp[v.back().second] + mod) % mod;
notdp[i] = (notdp[i] + fromdp) % mod;
dp[i] = dp[v.back().second];
dp[i] = (dp[i] + ((((h[i] * (h[i]+1))%mod)/2) * w[i]) % mod ) % mod;
v.push_back({h[i], i});
}
ll wyn = 0;
for(int i = 1; i <= n; i++)
{
wyn = (wyn + dp[i] + notdp[i]) % mod;
//cout << dp[i] << " " << notdp[i] << endl;
}
cout << wyn << endl;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
6484 KB |
Output is correct |
2 |
Incorrect |
1 ms |
6484 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
6484 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
6484 KB |
Output is correct |
2 |
Incorrect |
2 ms |
6484 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
6876 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
6484 KB |
Output is correct |
2 |
Incorrect |
1 ms |
6484 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
6648 KB |
Output is correct |
2 |
Incorrect |
2 ms |
6484 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
6484 KB |
Output is correct |
2 |
Incorrect |
1 ms |
6484 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |