#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define TranLeThanhTam "TranLeThanhTam"
#define all(v) v.begin(),v.end()
#define reset(a,i) memset(a,i,sizeof(a))
#define FOR(i,a,b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i,a,b) for (int i = (a), _b = (b); i >= _b; --i)
#define compact(v) sort(all(v)), v.erase(unique(all(v)), end(v))
#define sz(v) (int) v.size()
#define MASK(i) (1LL << (i)
#define BIT(i,x) ((x & MASK(i)) >> (i))
#define int ll
typedef long long ll;
typedef long double lb;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
const int Thanh_Tam = 1e5 + 17;
const int inf = 1e9 + 17;
const long long infll = 1e18 + 17;
const int MOD = 1e9 + 7;
const int Log = 18;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, 1, 0, -1};
const int max_block_size = 270;
const ll P = 311;
const int maxA = 1e2 + 17;
const int addi = 1e9;
const char dir[4] = {'W', 'S', 'N', 'E'};
const int Mod[3] = {998244353, MOD, 759186269};
ll mul(ll a, ll b, ll mod);
ll binpow(ll a, ll b, ll mod)
{
ll res = 1;
while (b > 0)
{
if (b & 1) res = mul(res,a,mod);
b >>= 1;
a = mul(a,a,mod);
}
return res;
}
ll add(ll a, ll b, ll mod) { return (a + b) % mod; }
ll sub(ll a, ll b, ll mod) { return (a - b + mod) % mod; }
ll mul(ll a, ll b, ll mod) { return ((a % mod) * (b % mod)) % mod; }
ll div(ll a, ll b, ll mod) { return mul(a, binpow(b, mod - 2, mod), mod); }
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand_range(ll l, ll r) { return uniform_int_distribution<ll>(l,r)(rng); }
int n;
int h[Thanh_Tam], w[Thanh_Tam], l[Thanh_Tam], r[Thanh_Tam];
ll pref_w[Thanh_Tam];
ll ans = 0;
stack<int> st;
vector<pii> order;
map<pair<int,pii>, bool> mp;
ll sum(int x)
{
return ((1LL * x * (x + 1)) >> 1) % MOD;
}
ll calc(int x, int y)
{
return (((1LL * sum(x)) % MOD) * ((1LL * sum(y)) % MOD)) % MOD;
}
ll merge(int x1, int y1, int x2, int y2)
{
if (x1 != x2) return 0;
return ((sum(x1) % MOD) * ((1LL * y1 * y2) % MOD)) % MOD;
}
void ThanhTam()
{
cin >> n;
FOR(i,1,n) cin >> h[i];
FOR(i,1,n) cin >> w[i];
//Prepare
FOR(i,1,n) pref_w[i] = add(pref_w[i - 1], w[i], MOD);
//Find left
while (!st.empty()) st.pop();
FOR(i,1,n)
{
while (!st.empty())
if (h[st.top()] >= h[i]) st.pop();
else break;
if (st.empty()) l[i] = 0;
else l[i] = st.top();
st.push(i);
}
//Find right
while (!st.empty()) st.pop();
FORD(i,n,1)
{
while (!st.empty())
if (h[st.top()] >= h[i]) st.pop();
else break;
if (st.empty()) r[i] = n + 1;
else r[i] = st.top();
st.push(i);
}
//Calculate answer
FOR(i,1,n)
if (!mp.count({h[i], {l[i], r[i]}}))
{
ans = add(ans, calc(sub(pref_w[r[i] - 1], pref_w[l[i]], MOD), h[i] - min(h[i], max(h[l[i]], h[r[i]]))), MOD);
mp[{h[i], {l[i], r[i]}}] = true;
ans = add(ans, merge(sub(pref_w[r[i] - 1], pref_w[l[i]], MOD), h[i] - min(h[i], max(h[l[i]], h[r[i]])), sub(pref_w[r[i] - 1], pref_w[l[i]], MOD), min(h[i], max(h[l[i]], h[r[i]]))), MOD);
}
cout << ans;
return;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
if (fopen(TranLeThanhTam".inp","r"))
{
freopen(TranLeThanhTam".inp","r",stdin);
freopen(TranLeThanhTam".out","w",stdout);
}
int t = 1;
//cin >> t;
while (t--)
ThanhTam();
return 0;
}
/*
2 * 4 => 30
2 * 2 => 9
2 * 3 => 18
2 * 1 => 3
Cách suy ra 2 * 4 từ 2 * 3 và 2 * 1
2 * 1 + 2 * 3 + 2 * 3 * 1 = 3 + 18 + 9 = 30 (Điều kiện: 2 cạnh đầu phải bằng nhau)
0
0 0
000
*/
Compilation message
fancyfence.cpp: In function 'int main()':
fancyfence.cpp:140:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
140 | freopen(TranLeThanhTam".inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fancyfence.cpp:141:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
141 | freopen(TranLeThanhTam".out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
2 ms |
2384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2520 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2384 KB |
Output is correct |
3 |
Correct |
12 ms |
4432 KB |
Output is correct |
4 |
Correct |
18 ms |
5456 KB |
Output is correct |
5 |
Correct |
23 ms |
6192 KB |
Output is correct |
6 |
Correct |
19 ms |
4944 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
3 ms |
2640 KB |
Output is correct |
3 |
Correct |
8 ms |
3408 KB |
Output is correct |
4 |
Correct |
20 ms |
4176 KB |
Output is correct |
5 |
Correct |
16 ms |
4176 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
1 ms |
2552 KB |
Output is correct |
3 |
Correct |
3 ms |
2640 KB |
Output is correct |
4 |
Correct |
9 ms |
3408 KB |
Output is correct |
5 |
Correct |
19 ms |
4188 KB |
Output is correct |
6 |
Correct |
17 ms |
4376 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
8 |
Correct |
4 ms |
3568 KB |
Output is correct |
9 |
Correct |
15 ms |
5968 KB |
Output is correct |
10 |
Correct |
41 ms |
13948 KB |
Output is correct |
11 |
Correct |
39 ms |
13896 KB |
Output is correct |
12 |
Correct |
1 ms |
2384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2552 KB |
Output is correct |
2 |
Correct |
2 ms |
2384 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2384 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
8 |
Correct |
2 ms |
2384 KB |
Output is correct |
9 |
Correct |
2 ms |
2384 KB |
Output is correct |
10 |
Correct |
1 ms |
2528 KB |
Output is correct |
11 |
Correct |
1 ms |
2384 KB |
Output is correct |
12 |
Correct |
2 ms |
2432 KB |
Output is correct |
13 |
Correct |
1 ms |
2640 KB |
Output is correct |
14 |
Correct |
1 ms |
2640 KB |
Output is correct |
15 |
Correct |
1 ms |
2640 KB |
Output is correct |
16 |
Correct |
1 ms |
2384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
2384 KB |
Output is correct |
2 |
Correct |
2 ms |
2384 KB |
Output is correct |
3 |
Correct |
1 ms |
2384 KB |
Output is correct |
4 |
Correct |
1 ms |
2640 KB |
Output is correct |
5 |
Correct |
1 ms |
2384 KB |
Output is correct |
6 |
Correct |
1 ms |
2384 KB |
Output is correct |
7 |
Correct |
1 ms |
2384 KB |
Output is correct |
8 |
Correct |
1 ms |
2384 KB |
Output is correct |
9 |
Correct |
1 ms |
2384 KB |
Output is correct |
10 |
Correct |
1 ms |
2384 KB |
Output is correct |
11 |
Correct |
11 ms |
4944 KB |
Output is correct |
12 |
Correct |
25 ms |
6736 KB |
Output is correct |
13 |
Correct |
32 ms |
7200 KB |
Output is correct |
14 |
Correct |
26 ms |
6164 KB |
Output is correct |
15 |
Correct |
1 ms |
2552 KB |
Output is correct |
16 |
Correct |
3 ms |
2908 KB |
Output is correct |
17 |
Correct |
9 ms |
4276 KB |
Output is correct |
18 |
Correct |
18 ms |
6224 KB |
Output is correct |
19 |
Correct |
18 ms |
6372 KB |
Output is correct |
20 |
Correct |
2 ms |
2640 KB |
Output is correct |
21 |
Correct |
4 ms |
3664 KB |
Output is correct |
22 |
Correct |
16 ms |
5968 KB |
Output is correct |
23 |
Correct |
42 ms |
13912 KB |
Output is correct |
24 |
Correct |
41 ms |
13904 KB |
Output is correct |
25 |
Correct |
1 ms |
2384 KB |
Output is correct |
26 |
Correct |
2 ms |
2384 KB |
Output is correct |
27 |
Correct |
1 ms |
2640 KB |
Output is correct |
28 |
Correct |
2 ms |
2640 KB |
Output is correct |
29 |
Correct |
2 ms |
2640 KB |
Output is correct |
30 |
Correct |
7 ms |
3676 KB |
Output is correct |
31 |
Correct |
6 ms |
3664 KB |
Output is correct |
32 |
Correct |
23 ms |
7928 KB |
Output is correct |
33 |
Correct |
28 ms |
8444 KB |
Output is correct |
34 |
Correct |
72 ms |
13812 KB |
Output is correct |
35 |
Correct |
59 ms |
13292 KB |
Output is correct |
36 |
Correct |
60 ms |
13896 KB |
Output is correct |
37 |
Correct |
58 ms |
13920 KB |
Output is correct |
38 |
Correct |
1 ms |
2384 KB |
Output is correct |
39 |
Correct |
60 ms |
13628 KB |
Output is correct |
40 |
Correct |
54 ms |
13900 KB |
Output is correct |
41 |
Correct |
39 ms |
14152 KB |
Output is correct |
42 |
Correct |
43 ms |
14408 KB |
Output is correct |