oj.uz

Submission #981053

# Submission time Handle Problem Language Result Execution time Memory
981053 2024-05-12T18:29:11 Z underwaterkillerwhale Tents (JOI18_tents) C++17
100 / 100
 174 ms 74740 KB 
#include <bits/stdc++.h>
#define se              second
#define fs              first
#define pb              push_back
#define ll              long long
#define ii              pair<ll,ll>
#define ld              long double
#define SZ(v)           (int)v.size()
#define ALL(v)          v.begin(), v.end()
#define bit(msk, i)     ((msk >> i) & 1)
#define iter(id, v)     for(auto id : v)
#define rep(i,m,n)      for(int i=(m); i<=(n); i++)
#define reb(i,m,n)      for(int i=(m); i>=(n); i--)

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now().time_since_epoch().count());
ll Rand(ll l, ll r) { return uniform_int_distribution<ll> (l, r)(rd); }

const int N = 3e3 + 7;
const ll Mod = 1e9 + 7;
const int szBL = 916;
const ll INF = 1e9;
const int BASE = 137;

int n, m;
ll dp[N][N], f[N][N];
ll fac[(int)1e5 + 7];

ll power (ll n, ll m) {
    if (m == 0) return 1;
    ll t = power(n, m >> 1);
    (t *= t) %= Mod;
    if (m & 1) (t *= n % Mod) %= Mod;
    return t;
}


ll C (int r, int n) {
    if (r > n) return 0;
    return fac[n] * power (fac[r], Mod - 2) % Mod * power (fac[n - r], Mod - 2) % Mod;
}

void fac_init () {
    fac[0] = 1;
    rep (i, 1, 1e5) fac[i] = fac[i - 1] * i % Mod;
}

void solution () {
    fac_init();
     cin >> n >> m;
     dp[0][m] = 1;
     rep (i, 1, n) {
         rep (j, 0, m) {
            (dp[i][j] += dp[i - 1][j + 1] * (j + 1) %Mod * 4 % Mod) %= Mod;
            if (j + 2 <= m) (dp[i][j] += dp[i - 1][j + 2] * ((1LL * (j + 2) * (j + 1) / 2) % Mod) % Mod) %= Mod;
            if (i - 2 >= 0 && j + 1 <= m) (dp[i][j] += dp[i - 2][j + 1] * (i - 1) % Mod * (j + 1) % Mod) %= Mod;
         }
     }
    ll res = 0;
     rep (i, 0, n) {
         ll delta = C(i, n);
         rep (j, 0, m) {
                (res += dp[i][j] * delta % Mod ) %= Mod;
        }
     }
     cout << res - 1<<"\n";
}



#define file(name) freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);

int main () {
//    file("c");
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    ll num_Test = 1;
//    cin >> num_Test;
    while(num_Test--)
        solution();
}
/*
18 3
2 5
6 21
13 19
9 17
14 17
19 20
2 16
2 10
9 14
19 20
14 16
1 3
17 19
14 21
18 19
4 7
5 12
1 13

*/

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 2 ms 4700 KB Output is correct
4 Correct 2 ms 5468 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Correct 2 ms 5504 KB Output is correct
7 Correct 2 ms 4956 KB Output is correct
8 Correct 2 ms 5724 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 3 ms 5980 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 4 ms 6348 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 2 ms 4700 KB Output is correct
4 Correct 2 ms 5468 KB Output is correct
5 Correct 2 ms 4956 KB Output is correct
6 Correct 2 ms 5504 KB Output is correct
7 Correct 2 ms 4956 KB Output is correct
8 Correct 2 ms 5724 KB Output is correct
9 Correct 2 ms 4956 KB Output is correct
10 Correct 3 ms 5980 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 4 ms 6348 KB Output is correct
13 Correct 1 ms 4700 KB Output is correct
14 Correct 6 ms 13956 KB Output is correct
15 Correct 115 ms 59216 KB Output is correct
16 Correct 9 ms 8028 KB Output is correct
17 Correct 26 ms 16732 KB Output is correct
18 Correct 33 ms 21232 KB Output is correct
19 Correct 130 ms 66788 KB Output is correct
20 Correct 104 ms 54868 KB Output is correct
21 Correct 72 ms 37992 KB Output is correct
22 Correct 69 ms 39560 KB Output is correct
23 Correct 43 ms 31064 KB Output is correct
24 Correct 174 ms 74740 KB Output is correct
25 Correct 132 ms 65276 KB Output is correct
26 Correct 148 ms 70484 KB Output is correct
27 Correct 165 ms 73024 KB Output is correct