oj.uz

Submission #401097

# Submission time Handle Problem Language Result Execution time Memory
401097 2021-05-09T11:04:26 Z NintsiChkhaidze Anagramistica (COCI21_anagramistica) C++14
110 / 110
 90 ms 716 KB 
#include <bits/stdc++.h>
#define pb push_back
#define mod 1000000007
#define ll long long
#define int long long
using namespace std;
const int N = 10005;
string s[N];
vector <int> v;
int dp[N],d[N],P[N];
ll go(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 C(int m,int n){
    ll x = P[n],y = P[m],z = P[n - m];
    y = (y*z)%mod;
    return (x * go(y, mod - 2))%mod;;
}
main (){
    ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
    int n,k;
    cin>>n>>k;
    
    for (int i=1;i<=n;i++){
        cin>>s[i];
        sort(s[i].begin(),s[i].end());
    }
    
    P[0] = 1;
    for (int i = 1; i <= 2000; i++)
        P[i] = (P[i - 1]*i)%mod;
        
    sort(s+1,s+n+1);
    int cnt=1;
    for (int i=1; i<=n; i++){
        if (s[i] != s[i + 1]) v.pb(cnt),cnt=0;
        cnt++;
    }
    
    ll ans=0;
    dp[0] = 1;
    for(int i=0; i <v.size();i++){
        for (int m = 1; m <= v[i]; m++){
            for (int j = 0; j <= 2000; j++){
                ll x = (m*(m - 1))/2;
                if (j + x > k) break; 
                d[j + x] = (dp[j]*C(m,v[i]) + d[j + x])%mod;
            }
        }
        
        for (int j=0;j<=2000;j++) 
            dp[j] = (dp[j] + d[j])%mod,d[j]=0;
    }
    cout<<dp[k];
}

Compilation message

anagramistica.cpp:25:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   25 | main (){
      |       ^
anagramistica.cpp: In function 'int main()':
anagramistica.cpp:48:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |     for(int i=0; i <v.size();i++){
      |                  ~~^~~~~~~~~
anagramistica.cpp:46:8: warning: unused variable 'ans' [-Wunused-variable]
   46 |     ll ans=0;
      |        ^~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 588 KB Output is correct
2 Correct 1 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 1 ms 588 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 588 KB Output is correct
2 Correct 3 ms 716 KB Output is correct
3 Correct 2 ms 652 KB Output is correct
4 Correct 4 ms 716 KB Output is correct

Subtask #3
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 588 KB Output is correct
2 Correct 1 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 1 ms 588 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 3 ms 716 KB Output is correct
8 Correct 2 ms 652 KB Output is correct
9 Correct 4 ms 716 KB Output is correct
10 Correct 21 ms 588 KB Output is correct
11 Correct 9 ms 588 KB Output is correct
12 Correct 2 ms 588 KB Output is correct
13 Correct 8 ms 588 KB Output is correct
14 Correct 13 ms 716 KB Output is correct
15 Correct 6 ms 588 KB Output is correct
16 Correct 55 ms 716 KB Output is correct
17 Correct 90 ms 588 KB Output is correct
18 Correct 3 ms 716 KB Output is correct