#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// Ofast, O0, O1, O2, O3, unroll-loops, fast-math, trapv
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define Mp make_pair
#define sep ' '
#define endl '\n'
#define F first
#define S second
#define pb push_back
#define all(x) (x).begin(),(x).end()
#define kill(res) cout << res << '\n', exit(0);
#define set_dec(x) cout << fixed << setprecision(x);
#define fast_io ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define file_io freopen("input.txt", "r", stdin) ; freopen("output.txt", "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll N = 1e5 + 50;
const ll Mod = 1e9 + 7;
ll n, h[N], w[N], pre[N], L[N], R[N], inv2;
vector<int> jahat, vv;
ll power(ll a, ll b, ll md = Mod){
ll ans = 1;
for(; b; b /= 2, a = a * a % md){
if(b % 2) ans = ans * a % md;
}
return ans;
}
ll c2(ll x){
return x * (x-1) % Mod * inv2 % Mod;
}
bool cmp(int i, int j){
return (Mp(h[i], i) < Mp(h[j], j));
}
int main(){
fast_io;
inv2 = power(2, Mod-2);
cin >> n;
for(int i = 1; i <= n; i++) cin >> h[i];
for(int i = 1; i <= n; i++){
cin >> w[i]; pre[i] = pre[i-1] + w[i];
}
vector<int> vec; vec.pb(0);
for(int i = 1; i <= n; i++){
while(h[vec.back()] >= h[i]) vec.pop_back();
L[i] = vec.back(); vec.pb(i);
}
vec.clear(); vec.pb(n+1);
for(int i = n; i > 0; i--){
while(h[vec.back()] >= h[i]) vec.pop_back();
R[i] = vec.back(); vec.pb(i);
}
for(int i = 1; i <= n; i++) jahat.pb(i);
sort(all(jahat), cmp);
vv.pb(jahat[0]);
for(int i = 1; i < n; i++) if(h[jahat[i-1]] != h[jahat[i]] || L[jahat[i-1]] != L[jahat[i]]) vv.pb(jahat[i]);
ll res = 0;
for(int i: vv){
ll mx = max(h[L[i]], h[R[i]]);
ll th1 = (h[i] - mx) * mx + (h[i] - mx) + c2(h[i] - mx); th1 %= Mod;
ll th2 = c2(pre[R[i]-1] - pre[L[i]]) + pre[R[i]-1] - pre[L[i]]; th2 %= Mod;
res = (res + th1 * th2) % Mod;
}
cout << res;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |