Submission #1097542

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097542		hiensumi	Trener (COCI20_trener)	C++14	110 / 110	30 ms	2908 KiB

trener

#include <bits/stdc++.h>
using namespace std;
#define fod(i,a,b) for(int i = (int) (a); i <= (int) (b); i++)
#define fok(i,a,b) for(int i = (int) (a); i >= (int) (b); i--)
#define ll long long
#define pb push_back
#define pii pair<int,int>
#define mp make_pair
#define fi first
#define se second
#define el '\n'
#define ve vector
#define vi ve<int>
#define vll ve<ll>
#define mask(a) (1LL<<(a))
#define BIT(msk,i) (msk>>(i)&1LL)
using namespace std;
template <class T> bool mini(T &a, T b){ return (a > (b)) ? a = (b), 1 : 0; }
template <class T> bool maxi(T &a, T b){ return (a < (b)) ? a = (b), 1 : 0; }
#define name "trener"

const int MOD = 1e9 + 7;

inline void madd(int &a, int b){
    a += b;
    if(a >= MOD) a -= MOD;
    else if(a < 0) a += MOD;
}

int n, k;

unordered_map <string, int> dp;

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0);
  
    cin >> n >> k;

    string s;
    fod(i,1,k){
        cin >> s;
        dp[s]++;
    }

    fod(i,2,n){
        unordered_map <string, int> new_dp;
        fod(j,1,k){
            string s; cin >> s;
            new_dp[s]++;
        }

        for(auto &x : new_dp){
            string x1 = x.fi.substr(0, i - 1);
            string x2 = x.fi.substr(1, i - 1);

            x.se = 1LL * x.se * (dp[x1] + (x1 != x2 ? dp[x2] : 0)) % MOD;
        }

        swap(dp, new_dp);
    }

    int res = 0;
    for(auto &x : dp) madd(res, x.se);

    cout << res;

    return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 55 / 55