#include <bits/stdc++.h>
#define ve vector
#define ld long double
#define ll long long
#define all(x) x.begin(), x.end()
#define fi first
#define se second
using namespace std;
using namespace chrono;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#pragma GCC optimize("Ofast")
const int MAXN = 1e5+10;
const ll mod = 1e9+7;
struct rect{
int h, w, id;
};
inline bool comp(const rect& r1, const rect& r2){
return r1.h < r2.h;
}
rect v[MAXN];
ll pref[MAXN];
int n;
ll binpow(ll a, ll n){
if(n == 0)
return 1;
if(n & 1)
return (a*binpow(a, n - 1))%mod;
ll t = binpow(a, n / 2);
return (t*t) % mod;
}
void solve(){
cin >> n;
set<int> del;
for(int i = 1; i <= n; i++)
cin >> v[i].h;
for(int i = 1; i <= n; i++)
cin >> v[i].w;
for(int i = 1; i <= n; i++)
v[i].id = i;
for(int i = 1; i <= n; i++)
pref[i] = (pref[i - 1] + v[i].w) % mod;
sort(v + 1, v + 1 + n, comp);
ve<int> add;
ll res = 0;
for(int i = 1; i <= n; i++){
auto it = del.lower_bound(v[i].id);
ll l, r;
if(it == del.end())
r = n;
else r = *it - 1;
if(it == del.begin())
l = 0;
else
l = *prev(it);
ll w = (pref[r] - pref[l] + mod) % mod;
ll pr = (w*(w - 1))%mod;
pr = (pr*binpow(2, mod - 2)) % mod;
pr = (pr + w) % mod;
ll ph;
if(i == 1)
ph = 0;
else ph = v[i - 1].h;
ll sum = ((ph + 1)+v[i].h)*(v[i].h - ph)/2;
pr = (pr*sum) % mod;
res = (res + pr) % mod;
del.insert(v[i].id);
}
cout << res;
}
signed main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int T = 1;
/* cin >> T; */
while(T--){
solve();
}
}
# |
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 |
Incorrect |
0 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 |
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 |
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 |
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 |
- |