oj.uz

Submission #236833

# Submission time Handle Problem Language Result Execution time Memory
236833 2020-06-03T14:18:01 Z aloo123 Tents (JOI18_tents) C++14
100 / 100
 247 ms 71160 KB 
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define mp make_pair
#define pb push_back
#define in insert
#define vll vector<ll>
#define endl "\n"
#define pll pair<ll,ll>
#define all(x) (x).begin() , (x).end()
#define f first
#define s second
#define pr(x) cout<<x<<endl;
#define pr2(x,y) cout<<x<<" "<<y<<endl;
#define pr3(x,y,z) cout<<x<<" "<<y<<endl;
#define prv(v) for(auto x:v) cout<<x<<" ";
#define ffs fflush(stdout);
#define int ll
#define sz(x) (ll)x.size()
using namespace std;
 
 
const ll MOD = 1e9+7;
const ll INF = LLONG_MAX;
const ll LOG = 29;
#define PI 3.141592653589793238 
 
 
 


const ll N =(2e5+5);

ll fact[N];

long long binpow(long long a, long long b) {
     a%=MOD;    
    long long res = 1;
    while (b > 0) {
        if (b & 1)
            res = (res * a)%MOD;
        a = (a * a)%MOD;
 
        
        b >>= 1;
    }
     res%=MOD;
    return res;
}
void ini(){
    fact[0] = 1;
    for(int i = 1;i < N;i++){
        fact[i] = (fact[i-1] * i)%MOD;
    }
}
ll ncr(ll n,ll r){
    ll ret = fact[n];
    ret = (ret * binpow(fact[r],MOD-2))%MOD;
    ret = (ret * binpow(fact[n-r],MOD-2))%MOD;
    return ret;
}
ll dp[3005][3005];
ll n,m;
ll recurse(ll i,ll j){
    if(i < 0 || j < 0){
        return 0;
    }
    else if(i == 0 || j == 0)return 1;
    if(dp[i][j] != -1)
        return dp[i][j];
    ll gg1 = i*(i-1);gg1/=2ll;
    gg1 = (gg1 * recurse(i-2,j-1))%MOD;
    ll gg2 = (4ll*i)%MOD;
    
    gg2 = (gg2 * recurse(i-1,j-1))%MOD;
    ll gg3 = recurse(i,j-1)%MOD;
    ll gg4 = i*(j-1);
    gg4 = (gg4 * recurse(i-1,j-2))%MOD;
    ll gg = gg1;
    gg = (gg + gg2)%MOD;
    gg = (gg + gg3)%MOD;
    gg = (gg + gg4)%MOD;
    return dp[i][j]= gg;

}

void solve(){
    cin >> n >> m;

    for(int i = 0;i<=n;i++){
        for(int j = 0;j<=m;j++){
            dp[i][j]=-1;
        }
    }
    cout << (recurse(n,m)-1+MOD)%MOD << endl;
        

}   
/*
5
abcab
aabab

aabbc
aaabb

*/

 
   
 
 
 /*
 2 3 4 5 6 1
 3 6 10 15 21 
 4 10 20 35 56 
 5 15 35 70 126 
 6 21 56 126 252 
*/
 
 
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    
       
 
     ll tt=1;
    while(tt--){
        solve();
    }    
}

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 512 KB Output is correct
4 Correct 5 ms 1152 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 5 ms 1408 KB Output is correct
7 Correct 5 ms 896 KB Output is correct
8 Correct 5 ms 1536 KB Output is correct
9 Correct 5 ms 896 KB Output is correct
10 Correct 6 ms 1792 KB Output is correct
11 Correct 5 ms 384 KB Output is correct
12 Correct 8 ms 2304 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 512 KB Output is correct
4 Correct 5 ms 1152 KB Output is correct
5 Correct 6 ms 768 KB Output is correct
6 Correct 5 ms 1408 KB Output is correct
7 Correct 5 ms 896 KB Output is correct
8 Correct 5 ms 1536 KB Output is correct
9 Correct 5 ms 896 KB Output is correct
10 Correct 6 ms 1792 KB Output is correct
11 Correct 5 ms 384 KB Output is correct
12 Correct 8 ms 2304 KB Output is correct
13 Correct 4 ms 384 KB Output is correct
14 Correct 8 ms 9728 KB Output is correct
15 Correct 139 ms 55452 KB Output is correct
16 Correct 18 ms 4224 KB Output is correct
17 Correct 44 ms 13104 KB Output is correct
18 Correct 49 ms 17296 KB Output is correct
19 Correct 162 ms 63232 KB Output is correct
20 Correct 139 ms 51072 KB Output is correct
21 Correct 107 ms 34048 KB Output is correct
22 Correct 84 ms 35584 KB Output is correct
23 Correct 29 ms 27136 KB Output is correct
24 Correct 247 ms 71160 KB Output is correct
25 Correct 186 ms 61568 KB Output is correct
26 Correct 201 ms 66936 KB Output is correct
27 Correct 231 ms 69368 KB Output is correct