oj.uz

Submission #987842

# Submission time Handle Problem Language Result Execution time Memory
987842 2024-05-23T16:39:19 Z VMaksimoski008 Fancy Fence (CEOI20_fancyfence) C++17
60 / 100
 296 ms 6484 KB 
#include <bits/stdc++.h>

#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
//#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

ll exp(ll a, ll b) {
    ll ans = 1;
    while(b) {
        if(b & 1) ans = (ans * a) % mod;
        a = (a * a) % mod;
        b /= 2;
    }
    return ans;
}

ll inv(ll a) {
    return exp(a, mod - 2);
}

ll C(ll a) {
    return a * (a + 1) % mod * inv(2) % mod;
}

ll S(ll l, ll r) {
    return (C(r) - C(l-1) + mod) % mod;
}

int32_t main() {
    ios_base::sync_with_stdio(false);
    cout.tie(0); cin.tie(0);

    int n;
    cin >> n;
    vector<ll> h(n+1), w(n+1);
    for(int i=1; i<=n; i++) cin >> h[i];
    for(int i=1; i<=n; i++) cin >> w[i];

    set<ll> s;
    for(int i=1; i<=n; i++) s.insert(h[i]);

    if(s.size() == 1) {
        ll W = 0, H = h[1];
        for(int i=1; i<=n; i++) W = (W + w[i]) % mod;
        cout << C(W) * C(H) % mod << '\n'; 
        return 0;
    }

    bool inc = true;
    for(int i=1; i<n; i++) if(h[i] > h[i+1]) inc = false;

    if(inc) {
        ll ans = 0, W = 0;

        for(int i=n; i>=1; i--) {
            W = (W + w[i]) % mod;
            ans = (ans + S(W-w[i]+1, W) * C(h[i])) % mod;
        }

        cout << ans << '\n';
        return 0;
    }

    if(n <= 1000) {
        ll ans = 0;

        vector<ll> pref(n+1);
        for(int i=1; i<=n; i++) pref[i] = (pref[i-1] + w[i]) % mod;

        auto query = [&](int l, int r) { return ( l > r ? 0 : (pref[r] - pref[l-1] + mod) % mod ); };

        for(int i=1; i<=n; i++) {
            ll H = h[i];
            for(int j=i+1; j<=n; j++) {
                H = min(H, h[j]);
                //cout << H << " " << query(i, j) << " " << query(i, j-1) << " " << query(i+1, j) << " " << query(i+1, j-1) << '\n';
                ans = (ans + C(H) * C(query(i, j)) % mod) % mod;
                ans = (ans - C(H) * C(query(i, j-1)) + mod % mod) % mod;
                ans = (ans - C(H) * C(query(i+1, j)) + mod % mod) % mod;
                ans = (ans + C(H) * C(query(i+1, j-1)) + mod % mod) % mod;
            }
        }

        for(int i=1; i<=n; i++) ans = (ans + C(w[i]) * C(h[i])) % mod;

        cout << ans << '\n';
        return 0;
    }

    return 0;
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 295 ms 504 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 1 ms 348 KB Output is correct

Subtask #3
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 294 ms 596 KB Output is correct
3 Incorrect 6 ms 1252 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 2 ms 604 KB Output is correct
3 Correct 8 ms 1116 KB Output is correct
4 Correct 18 ms 2040 KB Output is correct
5 Correct 16 ms 1884 KB Output is correct
6 Correct 1 ms 348 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 2 ms 604 KB Output is correct
4 Correct 9 ms 1112 KB Output is correct
5 Correct 19 ms 1884 KB Output is correct
6 Correct 17 ms 1880 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 7 ms 860 KB Output is correct
9 Correct 32 ms 2384 KB Output is correct
10 Correct 64 ms 6484 KB Output is correct
11 Correct 64 ms 6480 KB Output is correct
12 Correct 1 ms 348 KB Output is correct

Subtask #6
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 296 ms 500 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 292 ms 348 KB Output is correct
9 Correct 1 ms 344 KB Output is correct
10 Correct 2 ms 600 KB Output is correct
11 Correct 4 ms 344 KB Output is correct
12 Correct 73 ms 348 KB Output is correct
13 Correct 293 ms 348 KB Output is correct
14 Correct 293 ms 484 KB Output is correct
15 Correct 294 ms 484 KB Output is correct
16 Correct 1 ms 348 KB Output is correct

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 295 ms 504 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 293 ms 500 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 1 ms 344 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 292 ms 348 KB Output is correct
11 Incorrect 7 ms 1112 KB Output isn't correct
12 Halted 0 ms 0 KB -