Submission #999012

#	Time	Username	Problem	Language	Result	Execution time	Memory
999012		vjudge1	Trener (COCI20_trener)	C++17	110 / 110	171 ms	18384 KiB

trener

#include <bits/stdc++.h>

using namespace std;

#define int long long

const int mod = 1e9 + 7;

signed main()
{
	int n,k;
	cin>>n>>k;
	map<string,int> ans,cnt;
	int fin_ans=0,iv = (mod+1)/2;
	for (int a=1;a<=n;a++)
		for (int b=0;b<k;b++)
		{
			string s;
			cin>>s;
			cnt[s]++;
			if (a==1)
			{
				ans[s]=1;
				continue;
			}
			int x=0;
			string s1=s.substr(0,a-1),s2=s.substr(1,a-1);
			if (ans.find(s1)!=ans.end())
				x+=ans[s1]*cnt[s1]%mod;
			if (ans.find(s2)!=ans.end())
				x+=ans[s2]*cnt[s2]%mod;
			x%=mod;
			if (s1==s2)
				x=x*iv%mod;
			ans[s]=x;
			if (a==n)
				fin_ans+=x,fin_ans%=mod;
		}
	cout<<fin_ans<<endl;
	
	return 0;
}

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