Submission #777529

# Submission time Handle Problem Language Result Execution time Memory
777529 2023-07-09T10:15:34 Z qwerasdfzxcl Festivals in JOI Kingdom 2 (JOI23_festival2) C++17
100 / 100
6903 ms 8092 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() <= 100) 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 340 KB Output is correct
2 Correct 5 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 468 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 5 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 468 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 5 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 468 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 0 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 340 KB Output is correct
18 Correct 0 ms 468 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 5 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 468 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 0 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 340 KB Output is correct
18 Correct 0 ms 468 KB Output is correct
19 Correct 8 ms 468 KB Output is correct
20 Correct 8 ms 560 KB Output is correct
21 Correct 8 ms 532 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 340 KB Output is correct
2 Correct 5 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 468 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 0 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 340 KB Output is correct
18 Correct 0 ms 468 KB Output is correct
19 Correct 8 ms 468 KB Output is correct
20 Correct 8 ms 560 KB Output is correct
21 Correct 8 ms 532 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 2 ms 468 KB Output is correct
24 Correct 351 ms 1508 KB Output is correct
25 Correct 346 ms 1576 KB Output is correct
26 Correct 349 ms 1736 KB Output is correct
27 Correct 9 ms 528 KB Output is correct
28 Correct 78 ms 908 KB Output is correct
29 Correct 63 ms 792 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 5 ms 340 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 0 ms 468 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 468 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 0 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 0 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 0 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 340 KB Output is correct
18 Correct 0 ms 468 KB Output is correct
19 Correct 8 ms 468 KB Output is correct
20 Correct 8 ms 560 KB Output is correct
21 Correct 8 ms 532 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 2 ms 468 KB Output is correct
24 Correct 351 ms 1508 KB Output is correct
25 Correct 346 ms 1576 KB Output is correct
26 Correct 349 ms 1736 KB Output is correct
27 Correct 9 ms 528 KB Output is correct
28 Correct 78 ms 908 KB Output is correct
29 Correct 63 ms 792 KB Output is correct
30 Correct 6736 ms 7696 KB Output is correct
31 Correct 6903 ms 8092 KB Output is correct
32 Correct 6870 ms 7892 KB Output is correct
33 Correct 3624 ms 5656 KB Output is correct
34 Correct 1106 ms 2752 KB Output is correct
35 Correct 908 ms 2500 KB Output is correct