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Submission #1029618

# Submission time Handle Problem Language Result Execution time Memory
1029618 2024-07-21T06:09:24 Z atom Magneti (COCI21_magneti) C++17
10 / 110
 1 ms 856 KB 
#include "bits/stdc++.h"
// @JASPER'S BOILERPLATE
using namespace std;
using ll = long long;

#ifdef JASPER
#include "debug.h"
#else
#define debug(...) 166
#endif

const int MOD = 1e9 + 7;
const int N = 2e4 + 5;

int bPow(int a, int b) {
    ll ans = 1;
    while (b) {
        if (b & 1) ans = (1LL * ans * a)  % MOD;
        a = (1LL * a * a) % MOD;
        b >>= 1;
    }
    return ans;
}

int fac[N], inv[N];

void prepare() {
    fac[0] = 1;
    for (int i = 1; i < N; ++i)
        fac[i] = (1LL * fac[i - 1] * i) % MOD;

    inv[N - 1] = bPow(fac[N - 1], MOD - 2);
    for (int i = N - 2; i >= 0; --i)
        inv[i] = (1LL * inv[i + 1] * (i + 1)) % MOD;
}

int C(int k, int n) {
    if (k > n) return 0;
    return ((1LL * fac[n] * inv[n - k]) % MOD * (inv[k])) % MOD;
}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    
    #ifdef JASPER
        freopen("in1", "r", stdin);
    #endif

    prepare();

    int n, l;
    cin >> n >> l;
    vector <int> a(n + 1);
    for (int i = 1; i <= n; ++i) cin >> a[i];

    sort(a.begin(), a.end());
    if (a[1] == a[n]) {
        // sub1
        int p = (n - 1) * a[1] + 1;
        ll ans = (1LL * fac[n] * C(n, n + l - p)) % MOD;      
        cout << ans << "\n";  
    }
    
    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 608 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Correct 0 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 0 ms 604 KB Output is correct

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 856 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 604 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 608 KB Output is correct
2 Correct 1 ms 604 KB Output is correct
3 Correct 0 ms 604 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Correct 0 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 0 ms 604 KB Output is correct
11 Incorrect 1 ms 856 KB Output isn't correct
12 Halted 0 ms 0 KB -