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Submission #448796

# Submission time Handle Problem Language Result Execution time Memory
448796 2021-08-01T13:57:41 Z Aryan_Raina Fancy Fence (CEOI20_fancyfence) C++17
100 / 100
 49 ms 6268 KB 
#include <bits/stdc++.h>
using namespace std;
 
#define int int64_t
#define ld long double
#define ar array
#define all(a) a.begin(), a.end()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
const int INF = 1e12;
const int MOD = 1e9+7;
const int inv2 = 5e8+4;
  
struct UFDS {
    vector<int> p, wn;
    UFDS(int n) : p(n,-1), wn(n, 0) {}
    int fin(int v) { return p[v] < 0 ? v : p[v] = fin(p[v]); }
    bool join(int a, int b) {
        a = fin(a), b = fin(b);
        if (a == b) return false;
        if (-p[a] < -p[b]) swap(a, b);
        p[a] += p[b]; p[b] = a; (wn[a] += wn[b]) %= MOD;
        return true;
    }
};
 
void solve() {
    int N; cin >> N;
    vector<int> h(N), w(N);
    UFDS ufds(N);
    for (int &i : h) cin >> i;
    for (int &i : w) cin >> i;
    for (int i = 0; i < N; i++) ufds.wn[i] = w[i];
 
    vector<int> order(N);
    iota(order.begin(), order.end(), 0);
    sort(order.begin(), order.end(), [&](int a, int b) { return h[a] > h[b]; });
 
    int ans = 0;
    vector<bool> act(N, false);
    for (int x : order) {
        int lw = 0, rw = 0;
        if (x-1 >= 0 && act[x-1]) {
            lw = ufds.wn[ufds.fin(x-1)];
            ufds.join(x, x-1);
        }
        if (x+1 < N && act[x+1]) {
            rw = ufds.wn[ufds.fin(x+1)];
            ufds.join(x, x+1);
        }
 
        int a = (h[x] * (h[x] + 1) % MOD) * inv2 % MOD;
        int b = (w[x] * ufds.wn[ufds.fin(x)]) % MOD - ((w[x] - 1) * w[x] % MOD * inv2 % MOD);
        b = (b % MOD + MOD) % MOD;
 
        ans += (a * b % MOD) + ((lw * rw % MOD) * a % MOD) % MOD;
        ans %= MOD;
 
        act[x] = true;
    }
 
    ans = (ans + MOD) % MOD;
    cout << ans << '\n';
} 
 
int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0); 
 
    int t = 1; //cin >> t;
    while (t--) solve();   
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 15 ms 2764 KB Output is correct
4 Correct 29 ms 5392 KB Output is correct
5 Correct 31 ms 5380 KB Output is correct
6 Correct 29 ms 5380 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 4 ms 844 KB Output is correct
3 Correct 17 ms 3148 KB Output is correct
4 Correct 35 ms 6084 KB Output is correct
5 Correct 36 ms 6268 KB Output is correct
6 Correct 1 ms 204 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 312 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 4 ms 844 KB Output is correct
4 Correct 17 ms 3272 KB Output is correct
5 Correct 33 ms 6144 KB Output is correct
6 Correct 37 ms 6268 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 4 ms 844 KB Output is correct
9 Correct 18 ms 3280 KB Output is correct
10 Correct 33 ms 5964 KB Output is correct
11 Correct 33 ms 6136 KB Output is correct
12 Correct 0 ms 204 KB Output is correct

Subtask #6
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 312 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 328 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 1 ms 204 KB Output is correct

Subtask #7
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 15 ms 2884 KB Output is correct
12 Correct 29 ms 5372 KB Output is correct
13 Correct 30 ms 5380 KB Output is correct
14 Correct 30 ms 5316 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 4 ms 844 KB Output is correct
17 Correct 17 ms 3252 KB Output is correct
18 Correct 33 ms 6128 KB Output is correct
19 Correct 39 ms 6248 KB Output is correct
20 Correct 1 ms 332 KB Output is correct
21 Correct 4 ms 844 KB Output is correct
22 Correct 18 ms 3276 KB Output is correct
23 Correct 33 ms 6008 KB Output is correct
24 Correct 33 ms 6132 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct
30 Correct 5 ms 844 KB Output is correct
31 Correct 5 ms 844 KB Output is correct
32 Correct 20 ms 3160 KB Output is correct
33 Correct 22 ms 3148 KB Output is correct
34 Correct 44 ms 5880 KB Output is correct
35 Correct 40 ms 6000 KB Output is correct
36 Correct 49 ms 6164 KB Output is correct
37 Correct 46 ms 6180 KB Output is correct
38 Correct 1 ms 204 KB Output is correct
39 Correct 49 ms 6192 KB Output is correct
40 Correct 46 ms 6132 KB Output is correct
41 Correct 37 ms 6180 KB Output is correct
42 Correct 34 ms 6136 KB Output is correct