Submission #777534

# Submission time Handle Problem Language Result Execution time Memory
777534 2023-07-09T10:17:08 Z qwerasdfzxcl Festivals in JOI Kingdom 2 (JOI23_festival2) C++17
100 / 100
8978 ms 7720 KB
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
int n, MOD;

ll dpNAIVE[100100][2];
ll P[9][100100], Q[9][100100], R[9][100100], dp[100100][2];

ll fact[100100], factINV[100100];

inline void add(ll &x, const ll &y){
	x += y;
	if (x>=MOD) x -= MOD;
}

inline ll mul(const vector<ll> &a){
	ll ret = 1;
	for (auto &x:a) ret = ret * x % MOD;
	return ret;
}

inline ll mul(ll x, ll y){
	return x * y % MOD;
}

vector<ll> operator +(const vector<ll> &A, const vector<ll> &B){
	vector<ll> ret(max(A.size(), B.size()));
	for (int i=0;i<(int)ret.size();i++){
		if (i<(int)A.size()) add(ret[i], A[i]);
		if (i<(int)B.size()) add(ret[i], B[i]);
	}

	return ret;
}

vector<ll> cut(ll a[], int l, int r){
	vector<ll> ret(r-l+1);
	for (int i=0;i<(int)ret.size();i++) ret[i] = a[l+i];
	return ret;
}

vector<ll> cut(const vector<ll> &a, int l, int r){
	vector<ll> ret(r-l+1);
	for (int i=0;i<(int)ret.size();i++) ret[i] = a[l+i];
	return ret;	
}

ll pw(ll a, ll e){
	if (!e) return 1;
	ll ret = pw(a, e/2);
	if (e&1) return ret * ret % MOD * a % MOD;
	return ret * ret % MOD;
}

ll all(){
	ll ret = 1;
	for (int i=1;i<=n;i++) ret = ret * (i*2-1) % MOD;
	return ret;
}

void init(){
	fact[0] = 1;
	for (int i=1;i<=n*3+100;i++) fact[i] = fact[i-1] * i % MOD;
	factINV[n*3+100] = pw(fact[n*3+100], MOD-2);
	for (int i=n*3+99;i>=0;i--) factINV[i] = factINV[i+1] * (i+1) % MOD;
}

void naive(){
	dpNAIVE[2][0] = 1;
	dpNAIVE[1][1] = 1;

	for (int i=1;i<=n;i++){
		for (int j=0;i+j<=n;j++){
			if (i>1) add(dpNAIVE[i+j+2][0], mul({dpNAIVE[i][0], j+2, j+1, fact[2*i-2 + (j-1)], factINV[2*i-3]}));
			if (i>0) add(dpNAIVE[i+j+2][0], mul({dpNAIVE[i][1],      j+1, fact[2*i-1 + (j-1)], factINV[2*i-2]}));
			if (i>1) add(dpNAIVE[i+j+1][1], mul({dpNAIVE[i][0],      j+1, fact[2*i-2 + (j-1)], factINV[2*i-3]}));
			if (i>0) add(dpNAIVE[i+j+1][1], mul({dpNAIVE[i][1],           fact[2*i-1 + (j-1)], factINV[2*i-2]}));
		}
	}

	// for (int i=1;i<=n+1;i++){
	// 	printf("%d -> %lld %lld (naive)\n", i, dpNAIVE[i][0], dpNAIVE[i][1]);
	// }
}

vector<ll> naive(const vector<ll> &A, const vector<ll> &B){
	vector<ll> ret(A.size() + B.size() - 1);
	for (int i=0;i<(int)A.size();i++){
		for (int j=0;j<(int)B.size();j++){
			add(ret[i+j], A[i] * B[j] % MOD);
		}
	}

	return ret;
}

vector<ll> karatsuba(const vector<ll> &A, const vector<ll> &B){
	if (A.size() <= 200) return naive(A, B);

	int mid = (int)A.size() / 2;
	auto A2 = cut(A, 0, mid-1), A1 = cut(A, mid, (int)A.size()-1);
	auto B2 = cut(B, 0, mid-1), B1 = cut(B, mid, (int)B.size()-1);
	
	auto C1 = karatsuba(A1, B1), C2 = karatsuba(A2, B2), C3 = karatsuba(A1+A2, B1+B2);
	C2.resize(C1.size());

	// printf("ok size %d %d -> %d %d %d\n", (int)A1.size(), (int)A2.size(), (int)C1.size(), (int)C2.size(), (int)C3.size());

	assert(C1.size() == C2.size());
	assert(C1.size() == C3.size());
	
	vector<ll> ret(A.size()+B.size()-1);
	for (int i=0;i<(int)C1.size();i++) add(ret[i+mid*2], C1[i]);
	for (int i=0;i<(int)C2.size();i++) add(ret[i], C2[i]);
	for (int i=0;i<(int)C3.size();i++) add(ret[i+mid], (C3[i] - C1[i] - C2[i] + (ll)MOD*2) % MOD);

	return ret;
}

pair<vector<ll>, int> myConv(vector<ll> A, vector<ll> B){
	// C[j-i] = \sum A[i] * B[j]
	// ret[ofs+x] = C[x]

	// printf("A: ");
	// for (auto &x:A) printf("%lld ", x);
	// printf("\n");
	// printf("B: ");
	// for (auto &x:B) printf("%lld ", x);
	// printf("\n");

	int ofs = (int)A.size()-1;
	int sz = max(A.size(), B.size());
	assert(A.size() <= B.size());

	reverse(A.begin(), A.end());
	A.resize(sz);

	return {karatsuba(A, B), ofs};
}

void dnc(int l, int r){
	if (l==r){
		if (l==1){
			dp[1][0] = 0;
			dp[1][1] = 1;
		}

		else if (l==2){
			dp[2][0] = 1;
			dp[2][1] = 1;
		}

		else{
			add(dp[l][0], R[1][l]);
			add(dp[l][0], mul(R[2][l], (MOD-l*2+1)));
			add(dp[l][0], mul(R[3][l], mul(l, l)-l+MOD));
			
			add(dp[l][0], R[4][l]);
			add(dp[l][0], mul(R[5][l], l-1));

			add(dp[l][1], R[6][l]);
			// printf("ok dp[3][1] = %lld\n", dp[3][1]);
			add(dp[l][1], mul(R[7][l], l));
			// printf("ok dp[3][1] = %lld\n", dp[3][1]);

			add(dp[l][1], R[8][l]);
			// printf("ok dp[3][1] = %lld (%lld)\n", dp[3][1], R[8][l]);
		}

		if (l>=2){
			P[1][l] = mul({dp[l][0], l, l, factINV[2*l-3]});
			P[2][l] = mul({dp[l][0], l, factINV[2*l-3]});
			P[3][l] = mul(dp[l][0], factINV[2*l-3]);

			P[6][l] = mul({dp[l][0], MOD-l, factINV[2*l-3]});
			P[7][l] = mul(dp[l][0], factINV[2*l-3]);
		}

		if (l>=1){
			P[4][l] = mul({dp[l][1], MOD-l, factINV[2*l-2]});
			P[5][l] = mul(dp[l][1], factINV[2*l-2]);

			P[8][l] = mul(dp[l][1], factINV[2*l-2]);
		}

		// printf("%d -> %lld %lld\n", l, dp[l][0], dp[l][1]);

		return;
	}

	int m = (l+r)>>1;
	dnc(l, m);

	for (int k=1;k<=8;k++){
		auto [ret, ofs] = myConv(cut(P[k], l, m), cut(Q[k], m+1+l, m+r));

		// printf("Conv: ");
		// for (auto &x:ret) printf("%lld ", x);
		// printf("(ofs = %d)\n\n", ofs);
		for (int i=m+1;i<=r;i++) add(R[k][i], ret[ofs+(i-m-1)]);

		// if (k==8) printf("ok %lld\n", R[8][2]);
	}

	dnc(m+1, r);
}

void solve(){
	for (int i=0;i<=n*2+100;i++){
		if (i>=5) Q[1][i] = Q[2][i] = Q[3][i] = fact[i-5];
		if (i>=4) Q[4][i] = Q[5][i] = fact[i-4];
		if (i>=4) Q[6][i] = Q[7][i] = fact[i-4];
		if (i>=3) Q[8][i] = fact[i-3];
	}

	dnc(1, n+1);
}

int main(){
	scanf("%d %d", &n, &MOD);
	init();

	// printf("naive start\n");
	// auto st = clock();
	// naive();
	// printf("naive end: %fs\n", (double)(clock()-st)/CLOCKS_PER_SEC);
	// st = clock();
	// printf("solve start\n");
	solve();
	// printf("solve end: %fs\n", (double)(clock()-st)/CLOCKS_PER_SEC);

	// printf("ok %lld %lld\n", dpNAIVE[n+1][1], dp[n+1][1]);

	printf("%lld\n", (all() + MOD - dp[n+1][1]) % MOD);

}

Compilation message

festival2.cpp: In function 'int main()':
festival2.cpp:221:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  221 |  scanf("%d %d", &n, &MOD);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 428 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 428 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 432 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 428 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 432 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 428 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 428 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 432 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 428 KB Output is correct
19 Correct 9 ms 552 KB Output is correct
20 Correct 18 ms 524 KB Output is correct
21 Correct 10 ms 468 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 2 ms 468 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 428 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 432 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 428 KB Output is correct
19 Correct 9 ms 552 KB Output is correct
20 Correct 18 ms 524 KB Output is correct
21 Correct 10 ms 468 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 2 ms 468 KB Output is correct
24 Correct 447 ms 1532 KB Output is correct
25 Correct 445 ms 1544 KB Output is correct
26 Correct 449 ms 1500 KB Output is correct
27 Correct 11 ms 628 KB Output is correct
28 Correct 97 ms 908 KB Output is correct
29 Correct 100 ms 852 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 428 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 432 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 428 KB Output is correct
19 Correct 9 ms 552 KB Output is correct
20 Correct 18 ms 524 KB Output is correct
21 Correct 10 ms 468 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 2 ms 468 KB Output is correct
24 Correct 447 ms 1532 KB Output is correct
25 Correct 445 ms 1544 KB Output is correct
26 Correct 449 ms 1500 KB Output is correct
27 Correct 11 ms 628 KB Output is correct
28 Correct 97 ms 908 KB Output is correct
29 Correct 100 ms 852 KB Output is correct
30 Correct 8978 ms 7664 KB Output is correct
31 Correct 8944 ms 7720 KB Output is correct
32 Correct 8842 ms 7644 KB Output is correct
33 Correct 4630 ms 5632 KB Output is correct
34 Correct 1420 ms 2636 KB Output is correct
35 Correct 1171 ms 2432 KB Output is correct