oj.uz

Submission #987840

# Submission time Handle Problem Language Result Execution time Memory
987840 2024-05-23T16:38:53 Z VMaksimoski008 Fancy Fence (CEOI20_fancyfence) C++17
45 / 100
 295 ms 1884 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;
}

Compilation message

fancyfence.cpp: In function 'int32_t main()':
fancyfence.cpp:63:10: warning: variable 'inc' set but not used [-Wunused-but-set-variable]
   63 |     bool inc = true;
      |          ^~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 291 ms 504 KB Output is correct

Subtask #2
12.0 / 12.0

# 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 1 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 2 ms 344 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 293 ms 348 KB Output is correct
3 Incorrect 7 ms 1624 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 344 KB Output is correct
2 Correct 2 ms 600 KB Output is correct
3 Correct 10 ms 1116 KB Output is correct
4 Correct 16 ms 1884 KB Output is correct
5 Correct 17 ms 1884 KB Output is correct
6 Correct 1 ms 348 KB Output is correct

Subtask #5
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 2 ms 600 KB Output is correct
4 Correct 9 ms 1116 KB Output is correct
5 Correct 16 ms 1880 KB Output is correct
6 Correct 16 ms 1884 KB Output is correct
7 Correct 294 ms 516 KB Output is correct
8 Incorrect 3 ms 860 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #6
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 292 ms 344 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 1 ms 600 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 2 ms 348 KB Output is correct
8 Correct 292 ms 464 KB Output is correct
9 Correct 1 ms 344 KB Output is correct
10 Correct 293 ms 344 KB Output is correct
11 Correct 4 ms 344 KB Output is correct
12 Correct 75 ms 456 KB Output is correct
13 Correct 295 ms 524 KB Output is correct
14 Correct 293 ms 500 KB Output is correct
15 Correct 294 ms 348 KB Output is correct
16 Correct 1 ms 344 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 291 ms 504 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 294 ms 348 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 344 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 2 ms 348 KB Output is correct
10 Correct 292 ms 348 KB Output is correct
11 Incorrect 7 ms 1628 KB Output isn't correct
12 Halted 0 ms 0 KB -