CSES - Putka Open 2025 – 4/5

Submission details
Task:	Merkkijonot
Sender:	Sisuaski
Submission time:	2025-11-09 03:56:00 +0200
Language:	C++ (C++20)
Status:	READY
Result:	18

Feedback
group	verdict	score
#1	ACCEPTED	18
#2	WRONG ANSWER	0
#3	WRONG ANSWER	0
#4	WRONG ANSWER	0
#5	WRONG ANSWER	0

Test results
test	verdict	time	group
#1	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#2	ACCEPTED	0.01 s	2, 3, 4, 5	details
#3	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#4	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#5	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#6	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#7	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#8	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#9	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#10	ACCEPTED	0.01 s	1, 2, 3, 4, 5	details
#11	ACCEPTED	0.01 s	2, 3, 4, 5	details
#12	WRONG ANSWER	0.01 s	2, 3, 4, 5	details
#13	WRONG ANSWER	0.03 s	2, 3, 4, 5	details
#14	WRONG ANSWER	0.04 s	2, 3, 4, 5	details
#15	ACCEPTED	0.01 s	2, 3, 4, 5	details
#16	WRONG ANSWER	0.02 s	2, 3, 4, 5	details
#17	WRONG ANSWER	0.01 s	2, 3, 4, 5	details
#18	WRONG ANSWER	0.01 s	2, 3, 4, 5	details
#19	ACCEPTED	0.01 s	3, 4, 5	details
#20	WRONG ANSWER	0.02 s	3, 4, 5	details
#21	WRONG ANSWER	0.04 s	3, 4, 5	details
#22	WRONG ANSWER	0.04 s	3, 4, 5	details
#23	ACCEPTED	0.01 s	3, 4, 5	details
#24	WRONG ANSWER	0.03 s	3, 4, 5	details
#25	WRONG ANSWER	0.01 s	3, 4, 5	details
#26	WRONG ANSWER	0.01 s	3, 4, 5	details
#27	ACCEPTED	0.01 s	4, 5	details
#28	WRONG ANSWER	0.02 s	4, 5	details
#29	WRONG ANSWER	0.04 s	4, 5	details
#30	WRONG ANSWER	0.05 s	4, 5	details
#31	ACCEPTED	0.01 s	4, 5	details
#32	WRONG ANSWER	0.05 s	4, 5	details
#33	WRONG ANSWER	0.01 s	4, 5	details
#34	WRONG ANSWER	0.02 s	4, 5	details
#35	ACCEPTED	0.02 s	5	details
#36	WRONG ANSWER	0.02 s	5	details
#37	WRONG ANSWER	0.05 s	5	details
#38	WRONG ANSWER	0.06 s	5	details
#39	ACCEPTED	0.01 s	5	details
#40	WRONG ANSWER	0.08 s	5	details
#41	WRONG ANSWER	0.01 s	5	details
#42	WRONG ANSWER	0.02 s	5	details

Code

#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <unordered_map>
using namespace std;
typedef long long ll;

const int Z = 1e9+7;
const int A = 'z'-'a'+1;
struct Node {
	int cs[A];
};
Node nodes[10240];
int C;

struct NN {
	vector<int> out;
	int type;
	int par;

	bool operator==(const NN& n) const {
		if (type != n.type) return 0;
		if (out.size() != n.out.size()) return 0;
		for(size_t i=0; i<out.size(); ++i) if (out[i]!=n.out[i]) return 0;
		return 1;
	}
};
NN nns[10240];
int newIdx[10240];

struct NNH {
	size_t operator()(const NN& n) const {
		size_t h=n.type;
		for(size_t i=0; i<n.out.size(); ++i) {
			h = h*3333331 + n.out[i];
		}
		return h;
	}
};

int getP(int i) {
	if (nns[i].par==i) return i;
	return nns[i].par = getP(nns[i].par);
}
void normalize(int i) {
	NN& n = nns[i];
	for(int& x: n.out) {
		x = getP(x);
	}
	sort(n.out.begin(),n.out.end());
}

struct Mat {
	static const int MS = 100;
	int a[MS][MS];

	const int* operator[](int i)const{return a[i];}
	int* operator[](int i){return a[i];}
};

Mat operator*(const Mat& a, const Mat& b) {
	Mat m;
	for(int i=0; i<C; ++i) {
		for(int j=0; j<C; ++j) {
			ll r=0;
			for(int k=0; k<C; ++k) {
				r += a[i][k] * b[k][j] % Z;
			}
			m[i][j] = r % Z;
		}
	}
	return m;
}
Mat mpow(Mat m, int e) {
	if (e==1) return m;
	Mat r = mpow(m*m,e/2);
	return e&1 ? r*m : r;
}

string s;

void addPrefix(int ci, string cur) {
	Node& c = nodes[ci];
	cur.push_back(0);
	for(int i=0; i<A; ++i) {
		cur[cur.size()-1]='a'+i;
		if (c.cs[i]<0) {
			string x = cur;
			while(x != s.substr(0,x.size())) x = x.substr(1);
			if (!x.empty()) {
				c.cs[i] = x.size();
			}
		} else if (c.cs[i]>ci) {
			addPrefix(c.cs[i], cur);
		}
	}
}

int main() {
	int n,m;
	cin>>n>>m>>s;

	memset(nodes,-1,sizeof(nodes));

	for(int k=0; k<m; ++k) {
		for(char c='a'; c<='z'; ++c) {
			string cur = s.substr(0,k) + c;
			int x=cur.size();
			for(;x>0 && s.substr(0,x)!=cur.substr(cur.size()-x);x--);
			if (!x) continue;
			nodes[k].cs[c-'a'] = x;
		}
	}
	C = m+1;

	for(int k=m-1; k>=0; --k) {
		int ci = m;
		for(int j=k; j<m; ++j) {
			int x = s[j]-'a';
			Node& c = nodes[ci];
			if (j+1<m) {
				if (c.cs[x]<0) c.cs[x] = C++;
				ci = c.cs[x];
			} else c.cs[x] = m;
			if (ci==1) break;
		}
	}
	addPrefix(m, "");

	for(int i=0; i<C; ++i) {
		nns[i].type = i==0 ? 0 : i==m ? 1 : 2;
		nns[i].par=i;
		for(int j=0; j<A; ++j) {
			int t = nodes[i].cs[j];
			if (t<0) continue;
			nns[i].out.push_back(t);
		}
	}
	bool doMerge = 1;
	while(doMerge) {
		doMerge = 0;
		unordered_map<NN,int,NNH> nmap;
		for(int i=0; i<C; ++i) {
			auto it = nmap.find(nns[i]);
			if (it == nmap.end()) {
				nmap[nns[i]] = i;
			} else {
				nns[i].par = it->second;
				doMerge = 1;
			}
		}

		for(int i=0; i<C; ++i) {
			normalize(i);
		}

		int cc=0;
		for(int i=0; i<C; ++i) {
			if (nns[i].par != i) continue;
			newIdx[i] = cc;
			nns[cc] = nns[i];
			nns[cc].par = cc;
			cc++;
		}
		C = cc;

		for(int i=0; i<C; ++i) {
			for(int& x: nns[i].out) x = newIdx[x];
		}
	}

	int st=0,ed=0;
	for(int i=0; i<C; ++i) {
		if (nns[i].type==0) st=i;
		if (nns[i].type==1) ed=i;
	}

	Mat mat={};
	for(int i=0; i<C; ++i) {
		for(int t: nns[i].out) mat[i][t]++;
	}
	Mat res = mpow(mat,n);
	cout<<res[st][ed]<<'\n';
}

Test details

Test 1

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`1 1 a` view save

correct output
`1` view save

user output
`1` view save

Test 2

Group: 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 20 ssxfykmuzljmwgyvldnu` view save

correct output
`1` view save

user output
`1` view save

Test 3

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 10 aaaaaaaaaa` view save

correct output
`1` view save

user output
`1` view save

Test 4

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 10 aabbbaaaab` view save

correct output
`1532` view save

user output
`1532` view save

Test 5

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 10 aabbacbdca` view save

correct output
`1542` view save

user output
`1542` view save

Test 6

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 10 ztknszhrby` view save

correct output
`3261` view save

user output
`3261` view save

Test 7

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 1 a` view save

correct output
`1` view save

user output
`1` view save

Test 8

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 10 aabbbbbbba` view save

correct output
`1689` view save

user output
`1689` view save

Test 9

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 8 abxabyab` view save

correct output
`8619` view save

user output
`8619` view save

Test 10

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
`20 10 ababababab` view save

correct output
`509` view save

user output
`509` view save

Test 11

Group: 2, 3, 4, 5

Verdict: ACCEPTED

input
`100 50 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...` view save

correct output
`1` view save

user output
`1` view save

Test 12

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

input
`100 50 bbaaabbbbbabbbbabababababbbaab...` view save

correct output
`511493117` view save

user output
`83263915` view save

Feedback: Incorrect character on line 1 col 1: expected "511493117", got "83263915"

Test 13

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

input
`100 50 addabbbbbadddccadcabaacbbbaabd...` view save

correct output
`618572722` view save

user output
`448207441` view save

Feedback: Incorrect character on line 1 col 1: expected "618572722", got "448207441"

Test 14

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

input
`100 50 rrdumiqrjewanjplbyvkaytbcyzbyl...` view save

correct output
`35126431` view save

user output
`-955376902` view save

Feedback: Incorrect character on line 1 col 1: expected "35126431", got "-955376902"

Test 15

Group: 2, 3, 4, 5

Verdict: ACCEPTED

input
`100 1 a` view save

correct output
`1` view save

user output
`1` view save

Test 16

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

input
`100 50 aabbbbbbbbbbbbbbbbbbbbbbbbbbbb...` view save

correct output
`460606355` view save

user output
`163103641` view save

Feedback: Incorrect character on line 1 col 1: expected "460606355", got "163103641"

Test 17

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

input
`100 23 aybabtuxaybabtuyaybabtu` view save

correct output
`342213037` view save

user output
`-717469210` view save

Feedback: Incorrect character on line 1 col 1: expected "342213037", got "-717469210"

Test 18

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

input
`100 50 ababababababababababababababab...` view save

correct output
`775006564` view save

user output
`501479595` view save

Feedback: Incorrect character on line 1 col 1: expected "775006564", got "501479595"

Test 19

Group: 3, 4, 5

Verdict: ACCEPTED

input
`1000 50 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...` view save

correct output
`1` view save

user output
`1` view save

Test 20

Group: 3, 4, 5

Verdict: WRONG ANSWER

input
`1000 50 bbabaabbabbbaaaaaaaaaababaabbb...` view save

correct output
`911592620` view save

user output
`344011041` view save

Feedback: Incorrect character on line 1 col 1: expected "911592620", got "344011041"

Test 21

Group: 3, 4, 5

Verdict: WRONG ANSWER

input
`1000 50 cacabdddcbdadabdcbdddbdddbaccb...` view save

correct output
`12869296` view save

user output
`-440647150` view save

Feedback: Incorrect character on line 1 col 1: expected "12869296", got "-440647150"

Test 22

Group: 3, 4, 5

Verdict: WRONG ANSWER

input
`1000 50 tqoyadbshyehwcwaxbtbsqtaswkyet...` view save

correct output
`741984969` view save

user output
`-274374835` view save

Feedback: Incorrect character on line 1 col 1: expected "741984969", got "-274374835"

Test 23

Group: 3, 4, 5

Verdict: ACCEPTED

input
`1000 1 a` view save

correct output
`1` view save

user output
`1` view save

Test 24

Group: 3, 4, 5

Verdict: WRONG ANSWER

input
`1000 50 aabbbbbbbbbbbbbbbbbbbbbbbbbbbb...` view save

correct output
`599950419` view save

user output
`-613213226` view save

Feedback: Incorrect character on line 1 col 1: expected "599950419", got "-613213226"

Test 25

Group: 3, 4, 5

Verdict: WRONG ANSWER

input
`1000 23 aybabtuxaybabtuyaybabtu` view save

correct output
`548809016` view save

user output
`-617186460` view save

Feedback: Incorrect character on line 1 col 1: expected "548809016", got "-617186460"

Test 26

Group: 3, 4, 5

Verdict: WRONG ANSWER

input
`1000 50 ababababababababababababababab...` view save

correct output
`765799780` view save

user output
`-404703540` view save

Feedback: Incorrect character on line 1 col 1: expected "765799780", got "-404703540"

Test 27

Group: 4, 5

Verdict: ACCEPTED

input
`1000000 50 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...` view save

correct output
`1` view save

user output
`1` view save

Test 28

Group: 4, 5

Verdict: WRONG ANSWER

input
`1000000 50 bbaababbaaabbabababbaaaaaabbaa...` view save

correct output
`514073453` view save

user output
`-728177180` view save

Feedback: Incorrect character on line 1 col 1: expected "514073453", got "-728177180"

Test 29

Group: 4, 5

Verdict: WRONG ANSWER

input
`1000000 50 aabccabbbbabccabcdcdadbcdccdac...` view save

correct output
`438094288` view save

user output
`300773358` view save

Feedback: Incorrect character on line 1 col 1: expected "438094288", got "300773358"

Test 30

Group: 4, 5

Verdict: WRONG ANSWER

input
`1000000 50 yzfzimxrxfukhlkrtaylohyuqkupsn...` view save

correct output
`905445077` view save

user output
`748323805` view save

Feedback: Incorrect character on line 1 col 1: expected "905445077", got "748323805"

Test 31

Group: 4, 5

Verdict: ACCEPTED

input
`1000000 1 a` view save

correct output
`1` view save

user output
`1` view save

Test 32

Group: 4, 5

Verdict: WRONG ANSWER

input
`1000000 50 aabbbbbbbbbbbbbbbbbbbbbbbbbbbb...` view save

correct output
`280596224` view save

user output
`251799135` view save

Feedback: Incorrect character on line 1 col 2: expected "280596224", got "251799135"

Test 33

Group: 4, 5

Verdict: WRONG ANSWER

input
`1000000 23 aybabtuxaybabtuyaybabtu` view save

correct output
`268144314` view save

user output
`-610970266` view save

Feedback: Incorrect character on line 1 col 1: expected "268144314", got "-610970266"

Test 34

Group: 4, 5

Verdict: WRONG ANSWER

input
`1000000 50 ababababababababababababababab...` view save

correct output
`655244665` view save

user output
`-531147587` view save

Feedback: Incorrect character on line 1 col 1: expected "655244665", got "-531147587"

Test 35

Group: 5

Verdict: ACCEPTED

input
`1000000000 50 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...` view save

correct output
`1` view save

user output
`1` view save

Test 36

Group: 5

Verdict: WRONG ANSWER

input
`1000000000 50 abbbaabbaaaaabbbbabbabbaaaaaba...` view save

correct output
`911059863` view save

user output
`-539993096` view save

Feedback: Incorrect character on line 1 col 1: expected "911059863", got "-539993096"

Test 37

Group: 5

Verdict: WRONG ANSWER

input
`1000000000 50 cbabbcaadabbcabbdbdabbbcccbdca...` view save

correct output
`994268014` view save

user output
`-68995607` view save

Feedback: Incorrect character on line 1 col 1: expected "994268014", got "-68995607"

Test 38

Group: 5

Verdict: WRONG ANSWER

input
`1000000000 50 pehyicejeninplaczwezhahmbhwfwi...` view save

correct output
`837165971` view save

user output
`-613830403` view save

Feedback: Incorrect character on line 1 col 1: expected "837165971", got "-613830403"

Test 39

Group: 5

Verdict: ACCEPTED

input
`1000000000 1 a` view save

correct output
`1` view save

user output
`1` view save

Test 40

Group: 5

Verdict: WRONG ANSWER

input
`1000000000 50 aabbbbbbbbbbbbbbbbbbbbbbbbbbbb...` view save

correct output
`114333489` view save

user output
`-838940458` view save

Feedback: Incorrect character on line 1 col 1: expected "114333489", got "-838940458"

Test 41

Group: 5

Verdict: WRONG ANSWER

input
`1000000000 23 aybabtuxaybabtuyaybabtu` view save

correct output
`628064772` view save

user output
`366203809` view save

Feedback: Incorrect character on line 1 col 1: expected "628064772", got "366203809"

Test 42

Group: 5

Verdict: WRONG ANSWER

input
`1000000000 50 ababababababababababababababab...` view save

correct output
`802946327` view save

user output
`-161034258` view save

Feedback: Incorrect character on line 1 col 1: expected "802946327", got "-161034258"

Putka Open 2025 – 4/5

Merkkijonot

Code

Test details

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Test 8

Test 9

Test 10

Test 11

Test 12

Test 13

Test 14

Test 15

Test 16

Test 17

Test 18

Test 19

Test 20

Test 21

Test 22

Test 23

Test 24

Test 25

Test 26

Test 27

Test 28

Test 29

Test 30

Test 31

Test 32

Test 33

Test 34

Test 35

Test 36

Test 37

Test 38

Test 39

Test 40

Test 41

Test 42

Tasks

Submissions (Sisuaski)