#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// #include <ext/rope>
using namespace std;
// using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef long double ld;
template <class T>
using VV = vector<vector<T>>;
using VI = vector<int>;
using VVI = vector<vector<int>>;
using VL = vector<long long>;
using VVL = vector<vector<long long>>;
using VC = vector<char>;
using VVC = vector<vector<char>>;
using VB = vector<bool>;
using VVB = vector<vector<bool>>;
using VD = vector<double>;
using VVD = vector<vector<double>>;
using PII = pair<int, int>;
using PLL = pair<long long, long long>;
using PIL = pair<int, long long>;
using PLI = pair<long long, int>;
using VPII = vector<pair<int, int>>;
using VPLL = vector<pair<long long, long long>>;
#define LINE '\n'
#define SPACE ' '
#define PB push_back
#define FOR(i, a, b) for (int i = (a); i < (int(b)); i++)
#define FORE(i, a, b) for (int i = (a); i <= (int)((b)); i++)
#define ALL(x) x.begin(), x.end()
#define RALL(x) x.rbegin(), x.rend()
#define sq(a) ((a) * (a))
#define sz(x) ((int)x.size())
#define debug(x) cerr << #x << " = " << x << endl;
// zero indexed
template <class T>
struct segtree
{
const T def = 0;
int n;
vector<T> seg;
segtree(int _size) : n(_size), seg(2 * _size, def) {}
T merge(T a, T b)
{
return max(a, b);
}
void update(int pos, T val)
{
for (seg[pos += n] = val; pos /= 2;)
{
seg[pos] = merge(seg[pos * 2], seg[pos * 2 + 1]);
}
}
T query(int l, int r)
{ // get [l, r]
T a = def, b = def;
for (l += n, r += n + 1; l < r; l /= 2, r /= 2)
{
if (l % 2)
a = merge(a, seg[l++]);
if (r % 2)
b = merge(b, seg[--r]);
}
return merge(a, b);
}
};
const ll MOD = 1e9 + 7;
template <class T>
void maxi(T &a, T b)
{
a = max(a, b);
}
template <class T>
void mini(T &a, T b)
{
a = min(a, b);
}
template <class T>
void addi(T &a, T b)
{
a = (a + b) % MOD;
}
template <class T>
void subi(T &a, T b)
{
a = (a - b + MOD) % MOD;
}
template <class T>
T add(T a, T b)
{
return (a + b) % MOD;
}
template <class T>
T sub(T a, T b)
{
return (a - b + MOD) % MOD;
}
template <class T>
T mul(T a, T b)
{
return ((a % MOD) * (b % MOD)) % MOD;
}
ll binpow(ll a, ll b, ll mod)
{
ll res = 1;
while (b > 0)
{
if (b & 1)
{
res = (res * a) % mod;
}
a = (a * a) % mod;
b >>= 1;
}
return res;
}
const int INF = 1e9;
const int MAX_N = 1e5 + 3;
struct SEG
{
ll h, w, sum;
};
void solve()
{
int n;
cin >> n;
VL h(n);
VL w(n);
FOR(i, 0, n)
cin >> h[i];
FOR(i, 0, n)
cin >> w[i];
stack<SEG> st;
ll ans = 0;
ll inv = binpow(2, MOD - 2, MOD);
FOR(i, 0, n)
{
ll w_sum = 0;
while (sz(st) && st.top().h >= h[i])
{
addi(w_sum, st.top().sum);
//w_sum += st.top().sum;
st.pop();
}
ll h_val = mul(mul(h[i], h[i] + 1), inv);
ll w_val = mul(mul(w[i], w[i] + 1), inv);
if(!sz(st) && w_sum) {
ll val = h_val;
val = mul(val, w[i]);
val = mul(val, w_sum);
//ll val = w_sum * w[i] * (h[i] * (h[i] + 1) * inv);
addi(ans, val);
}
//ll t1 = w[i] * (w[i] + 1) * inv * h[i] * (h[i] + 1) * inv;
ll t1 = mul(h_val, w_val);
t1 %= MOD;
addi(ans, t1);
ll new_sum = 0;
if(sz(st)) {
auto [h_seg, w_seg, sum_seg] = st.top();
//ll t2 = sum_seg * (w[i]);
ll t2 = mul(sum_seg, w[i]);
addi(ans, t2);
new_sum = sum_seg;
}
addi(new_sum, mul(w[i], h_val));
//new_sum += w[i] * h[i] * (h[i] + 1) * inv;
st.push({w_sum, h[i], new_sum});
}
cout << ans << LINE;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
// cin >> t;
while (t--)
solve();
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Incorrect |
0 ms |
356 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 |
600 KB |
Output is correct |
2 |
Incorrect |
0 ms |
440 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
2 ms |
864 KB |
Output is correct |
3 |
Correct |
8 ms |
3284 KB |
Output is correct |
4 |
Correct |
22 ms |
6240 KB |
Output is correct |
5 |
Correct |
18 ms |
6488 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
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 |
2 ms |
860 KB |
Output is correct |
4 |
Correct |
9 ms |
3420 KB |
Output is correct |
5 |
Correct |
17 ms |
6380 KB |
Output is correct |
6 |
Correct |
19 ms |
6496 KB |
Output is correct |
7 |
Correct |
1 ms |
352 KB |
Output is correct |
8 |
Correct |
2 ms |
1112 KB |
Output is correct |
9 |
Correct |
9 ms |
3420 KB |
Output is correct |
10 |
Correct |
17 ms |
6116 KB |
Output is correct |
11 |
Correct |
17 ms |
6236 KB |
Output is correct |
12 |
Correct |
0 ms |
352 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Incorrect |
1 ms |
356 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Incorrect |
0 ms |
356 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |