QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#325597#7956. Walk Swappingmateberishvili#WA 123ms3844kbC++233.6kb2024-02-11 17:39:412024-02-11 17:39:41

Judging History

This is the latest submission verdict.

  • [2024-02-11 17:39:41]
  • Judged
  • Verdict: WA
  • Time: 123ms
  • Memory: 3844kb
  • [2024-02-11 17:39:41]
  • Submitted

answer

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int MAXN = (int) 3e3 + 5;
const int MOD = (int) 1e9 + 7;
const int P = 3491;

int add(int a, int b, int m = MOD) {
	return a + b < m ? a + b : a + b - m;
}

int mul(int a, int b, int m = MOD) {
	return a * 1ll * b % m;
}

int bpow(int a, int b, int m = MOD) {
	int res = 1;
	
	for (; b; b /= 2) {
		if (b & 1) {
			res = mul(res, a, m);
		}
		a = mul(a, a, m);
	}
	
	return res;
}

const int P_inv = bpow(P, MOD - 2);

int pw[MAXN];
int n;

void pre() {
	pw[0] = 1;
	
	for (int i = 1; i < MAXN; i++) {
		pw[i] = mul(pw[i - 1], P);
	}
}

map<vector<int>, int> gen(vector<int> A) {
	queue<pair<vector<int>, int>> Q;
	set<pair<vector<int>, int>> S;
	map<pair<vector<int>, int>, int> D;
	map<vector<int>, int> ans;
	
	for (int st = 0; st < n; st++) {
		Q.push({A, st});
		S.insert({A, st});
		D[{A, st}] = 0;
	}
	
	ans[A] = 0;
	
	while (!Q.empty()) {
		vector<int> v = Q.front().first;
		int pos = Q.front().second;
		Q.pop();
		
		if (!ans[v]) {
			ans[v] = D[{v, pos}];
		}
		
		for (int d: {-1, +1}) {
			int new_pos = (pos + d + n) % n;
			vector<int> new_v = v;
			swap(new_v[pos], new_v[new_pos]);
			if (!S.count({new_v, new_pos})) {
				D[{new_v, new_pos}] = D[{v, pos}] + 1;
				S.insert({new_v, new_pos});
				Q.push({new_v, new_pos});
			}
		}
	}
	
	return ans;
}

int pref[MAXN];

int calc_fast(vector<int> A, vector<int> B) {
	if (A == B) {
		return 0;
	}
	
	vector<pair<int, int>> M;
	
	for (int i = 0; i < n; i++) {
		vector<int> nB = B;
		rotate(nB.begin(), nB.begin() + i, nB.end());
		int hsh = 0;
		
		for (int j = 0; j < n; j++) {
			hsh = add(hsh, mul(nB[j], pw[j]));
		}
		
		M.push_back({hsh, (n - i) % n});
	}
	
	sort(M.begin(), M.end());
	
	int ans = (int) 1e9;
	
	for (int l = 0; l < n; l++) {
		for (int i = 0; i < n; i++) {
			pref[i] = add(mul(pw[i], A[i]), i > 0 ? pref[i - 1] : 0);
		}
		
		for (int len = 2; len <= n; len++) {
			int suf_part = add(pref[n - 1], MOD - pref[len-1]);
			int hsh_A = add(mul(add(pref[len - 1], MOD - pref[0]), P_inv), mul(pref[0], pw[len - 1]));
			int hsh_B = add(mul(pref[len - 2], P), A[len - 1]);
			
			for (int h: {hsh_A, hsh_B}) {
				int rot = (n - l) % n;
				int hsh = add(h, suf_part);				
				auto it = lower_bound(M.begin(), M.end(), make_pair(hsh, rot));
				
				if (it != M.end() && it->first == hsh) {
					int cur = len - 1;
					int pp = it->second;
					cur += min(abs(pp - rot), n - abs(pp - rot)) * (n - 1);                             
					ans = min(ans, cur);
				}
				
				if (it != M.begin() && prev(it)->first == hsh) {
					int cur = len - 1;
					int pp = prev(it)->second;
					cur += min(abs(pp - rot), n - abs(pp - rot)) * (n - 1);                             
					ans = min(ans, cur);
				}
			}
		}
		
		rotate(A.begin(), A.begin() + 1, A.end());
	}
	
	return ans == 1e9 ? -1 : ans;
}

int main() {
	pre();
	
	cin >> n;
	vector<int> A(n), B(n);
	
	for (int i = 0; i < n; i++) {
		cin >> A[i];
	}
	
	for (int i = 0; i < n; i++) {
		cin >> B[i];
	}
	
	cout << calc_fast(A, B) << '\n';
	
//	map<vector<int>, int> D = gen(A);
//	
//	vector<int> P(n);
//	iota(P.begin(), P.end(), 1);
//	
//	do {
//		auto it = D.find(P);
//		int ans_slow = (it == D.end() ? -1 : it -> second);
//		int ans_fast = calc_fast(A, P);
//		
//		if (ans_slow != ans_fast) {
//			for (int i = 0; i < n; i++) {
//				cout << P[i] << ' ';
//			}
//			cout << endl;
//			cout << ans_slow << ' ' << ans_fast << endl;
//			exit(0);
//		}
//	}
//	while (next_permutation(P.begin(), P.end()));
	
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3512kb

input:

4
4 3 2 1
3 4 2 1

output:

1

result:

ok single line: '1'

Test #2:

score: 0
Accepted
time: 0ms
memory: 3516kb

input:

6
2 1 1 2 2 1
1 2 2 2 1 1

output:

7

result:

ok single line: '7'

Test #3:

score: 0
Accepted
time: 0ms
memory: 3636kb

input:

6
4 1 3 6 2 5
6 2 1 3 4 5

output:

-1

result:

ok single line: '-1'

Test #4:

score: 0
Accepted
time: 0ms
memory: 3828kb

input:

4
1 2 3 4
4 2 1 3

output:

2

result:

ok single line: '2'

Test #5:

score: 0
Accepted
time: 0ms
memory: 3604kb

input:

6
4 1 3 6 2 5
6 2 5 3 4 1

output:

13

result:

ok single line: '13'

Test #6:

score: 0
Accepted
time: 0ms
memory: 3636kb

input:

6
4 1 3 3 2 5
3 2 5 3 4 1

output:

12

result:

ok single line: '12'

Test #7:

score: 0
Accepted
time: 0ms
memory: 3628kb

input:

4
4 3 2 1
1 3 2 4

output:

1

result:

ok single line: '1'

Test #8:

score: 0
Accepted
time: 0ms
memory: 3564kb

input:

5
4 3 5 2 1
1 3 5 4 2

output:

2

result:

ok single line: '2'

Test #9:

score: 0
Accepted
time: 0ms
memory: 3640kb

input:

5
4 3 5 2 1
1 4 3 5 2

output:

4

result:

ok single line: '4'

Test #10:

score: 0
Accepted
time: 0ms
memory: 3636kb

input:

5
1 1 1 2 1
2 1 1 1 1

output:

2

result:

ok single line: '2'

Test #11:

score: 0
Accepted
time: 0ms
memory: 3844kb

input:

4
4 3 2 1
1 3 2 4

output:

1

result:

ok single line: '1'

Test #12:

score: 0
Accepted
time: 0ms
memory: 3516kb

input:

4
4 3 2 1
1 3 4 2

output:

2

result:

ok single line: '2'

Test #13:

score: 0
Accepted
time: 0ms
memory: 3764kb

input:

10
2 3 1 1 3 4 5 5 6 1
1 1 3 4 5 3 5 1 7 2

output:

-1

result:

ok single line: '-1'

Test #14:

score: 0
Accepted
time: 0ms
memory: 3640kb

input:

5
1 4 5 3 2
5 3 2 1 4

output:

8

result:

ok single line: '8'

Test #15:

score: 0
Accepted
time: 0ms
memory: 3576kb

input:

5
1 2 3 4 5
5 2 1 3 4

output:

3

result:

ok single line: '3'

Test #16:

score: 0
Accepted
time: 0ms
memory: 3556kb

input:

10
1 2 3 4 5 6 7 8 9 10
8 4 2 3 1 5 7 6 9 10

output:

-1

result:

ok single line: '-1'

Test #17:

score: 0
Accepted
time: 0ms
memory: 3792kb

input:

10
1 2 3 2 2 2 1 1 1 1
2 1 1 1 1 1 2 2 3 2

output:

41

result:

ok single line: '41'

Test #18:

score: 0
Accepted
time: 0ms
memory: 3628kb

input:

10
1 1 1 2 2 4 4 4 2 2
1 1 2 2 4 4 2 2 1 4

output:

12

result:

ok single line: '12'

Test #19:

score: 0
Accepted
time: 0ms
memory: 3580kb

input:

12
3 3 3 2 2 2 4 4 2 2 1 3
3 3 2 2 4 4 2 2 2 1 3 3

output:

13

result:

ok single line: '13'

Test #20:

score: 0
Accepted
time: 0ms
memory: 3628kb

input:

12
3 3 2 2 2 2 4 4 2 2 1 2
2 2 2 2 4 4 2 2 2 1 3 3

output:

19

result:

ok single line: '19'

Test #21:

score: 0
Accepted
time: 0ms
memory: 3612kb

input:

12
3 3 2 4 2 2 4 4 2 2 1 2
2 2 2 2 4 4 2 2 4 1 3 3

output:

-1

result:

ok single line: '-1'

Test #22:

score: 0
Accepted
time: 0ms
memory: 3628kb

input:

20
3 4 4 5 1 2 3 2 5 1 1 5 3 2 4 5 1 2 3 5
2 3 5 4 4 5 1 2 3 2 5 3 1 1 5 3 2 4 5 1

output:

49

result:

ok single line: '49'

Test #23:

score: 0
Accepted
time: 0ms
memory: 3632kb

input:

20
3 4 4 5 1 2 3 2 5 1 1 5 3 2 4 5 1 2 3 5
3 2 3 4 5 1 2 3 5 4 4 5 1 2 3 2 5 1 1 5

output:

158

result:

ok single line: '158'

Test #24:

score: 0
Accepted
time: 1ms
memory: 3632kb

input:

100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
99 1...

output:

109

result:

ok single line: '109'

Test #25:

score: 0
Accepted
time: 0ms
memory: 3768kb

input:

100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
100 ...

output:

89

result:

ok single line: '89'

Test #26:

score: 0
Accepted
time: 1ms
memory: 3640kb

input:

100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
51 5...

output:

4924

result:

ok single line: '4924'

Test #27:

score: 0
Accepted
time: 1ms
memory: 3624kb

input:

100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
51 5...

output:

4905

result:

ok single line: '4905'

Test #28:

score: 0
Accepted
time: 1ms
memory: 3640kb

input:

100
1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 10 10 10 10 10 11 11 11 11 11 12 12 12 12 12 13 13 13 13 13 14 14 14 14 14 15 15 15 15 15 16 16 16 16 16 17 17 17 17 17 18 18 18 18 18 19 19 19 19 19 20 20 20 20 20
9 9 9 9 9 10 10 10 10 10 11 11 11 11 11 1...

output:

3990

result:

ok single line: '3990'

Test #29:

score: 0
Accepted
time: 1ms
memory: 3624kb

input:

100
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1
3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 ...

output:

125

result:

ok single line: '125'

Test #30:

score: 0
Accepted
time: 1ms
memory: 3640kb

input:

100
1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 10 10 10 10 10 11 11 11 11 11 12 12 12 12 12 13 13 13 13 13 14 14 14 14 14 15 15 15 15 15 16 16 16 16 16 17 17 17 17 17 18 18 18 18 18 19 19 19 19 19 20 20 20 20 20
9 9 9 9 9 10 10 10 10 10 11 11 11 15 11 1...

output:

-1

result:

ok single line: '-1'

Test #31:

score: 0
Accepted
time: 1ms
memory: 3572kb

input:

100
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1
2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 ...

output:

79

result:

ok single line: '79'

Test #32:

score: 0
Accepted
time: 1ms
memory: 3632kb

input:

100
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1
2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

output:

-1

result:

ok single line: '-1'

Test #33:

score: 0
Accepted
time: 0ms
memory: 3640kb

input:

100
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 ...

output:

0

result:

ok single line: '0'

Test #34:

score: -100
Wrong Answer
time: 123ms
memory: 3612kb

input:

1000
458 51 4 190 103 444 401 456 34 970 169 517 283 66 571 282 233 161 32 376 168 616 993 347 213 597 334 652 471 532 552 987 353 613 665 305 477 632 331 293 939 598 175 813 10 890 423 560 502 857 277 18 283 461 6 231 233 648 929 75 896 807 900 2 582 84 81 107 255 145 909 562 492 58 218 575 7 610 6...

output:

13946

result:

wrong answer 1st lines differ - expected: '243210', found: '13946'