oj.uz

Submission #57629

# Submission time Handle Problem Language Result Execution time Memory
57629 2018-07-15T14:54:24 Z Benq Tents (JOI18_tents) C++14
100 / 100
 315 ms 36032 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

int dp[3001][3001];

int ad(int a, int b) { return (a+b)%MOD; }
int mul(int a, int b) { return (ll)a*b%MOD; }

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    F0R(i,3001) dp[i][0] = dp[0][i] = 1;
    FOR(x,1,3001) FOR(y,1,3001) { // rows, cols
        if (y > 1) dp[x][y] = ad(dp[x][y],mul(y*(y-1)/2,dp[x-1][y-2]));
        if (x > 1) dp[x][y] = ad(dp[x][y],mul((x-1)*y,dp[x-2][y-1]));
        dp[x][y] = ad(dp[x][y],mul(4*y,dp[x-1][y-1]));
        dp[x][y] = ad(dp[x][y],dp[x-1][y]);
    }
    int a,b; cin >> a >> b; 
    cout << (dp[a][b]+MOD-1)%MOD;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 191 ms 35576 KB Output is correct
2 Correct 193 ms 35684 KB Output is correct
3 Correct 228 ms 35684 KB Output is correct
4 Correct 244 ms 35780 KB Output is correct
5 Correct 192 ms 35800 KB Output is correct
6 Correct 251 ms 35800 KB Output is correct
7 Correct 291 ms 35800 KB Output is correct
8 Correct 190 ms 35944 KB Output is correct
9 Correct 181 ms 35944 KB Output is correct
10 Correct 185 ms 35944 KB Output is correct
11 Correct 182 ms 35944 KB Output is correct
12 Correct 183 ms 35944 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 191 ms 35576 KB Output is correct
2 Correct 193 ms 35684 KB Output is correct
3 Correct 228 ms 35684 KB Output is correct
4 Correct 244 ms 35780 KB Output is correct
5 Correct 192 ms 35800 KB Output is correct
6 Correct 251 ms 35800 KB Output is correct
7 Correct 291 ms 35800 KB Output is correct
8 Correct 190 ms 35944 KB Output is correct
9 Correct 181 ms 35944 KB Output is correct
10 Correct 185 ms 35944 KB Output is correct
11 Correct 182 ms 35944 KB Output is correct
12 Correct 183 ms 35944 KB Output is correct
13 Correct 185 ms 35944 KB Output is correct
14 Correct 206 ms 35944 KB Output is correct
15 Correct 215 ms 35996 KB Output is correct
16 Correct 204 ms 36000 KB Output is correct
17 Correct 200 ms 36000 KB Output is correct
18 Correct 194 ms 36000 KB Output is correct
19 Correct 188 ms 36000 KB Output is correct
20 Correct 203 ms 36000 KB Output is correct
21 Correct 203 ms 36000 KB Output is correct
22 Correct 220 ms 36012 KB Output is correct
23 Correct 212 ms 36012 KB Output is correct
24 Correct 219 ms 36012 KB Output is correct
25 Correct 315 ms 36032 KB Output is correct
26 Correct 198 ms 36032 KB Output is correct
27 Correct 223 ms 36032 KB Output is correct