Submission #1076541

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076541		surgutti	Brperm (RMI20_brperm)	C++14	100 / 100	264 ms	172220 KiB

brperm

#include "brperm.h"

typedef long long LL;

const LL mod = 1e9 + 696969;
const LL base = 2137;

const int L = 20;
const int N = 1 << L;

int n;
LL pw[N + 1], h1[L][N], h2[L][N];

void init(int _n, const char s[]) {
	n = _n;
	pw[0] = 1;
	for (int i = 1; i <= N; i++)
		pw[i] = pw[i - 1] * base % mod;
	
	for (int h = 0; h < L; h++)
		for (int i = n - 1; i >= 0; i--)
			h1[h][i] = (s[i] + h1[h][i + 1] * pw[1 << h]) % mod;

	for (int i = 0; i < n; i++)
		h2[0][i] = s[i];
	
	for (int h = 0; h + 1 < L; h++)
		for (int i = 0; i < n; i++)
			h2[h + 1][i] = (h2[h][i] + pw[(1 << (L - 2 - h))] * h2[h][i + (1 << h)]) % mod;
}

int query(int i, int k) {
	if (i + (1 << k) > n)
		return 0;

	int l = L - 1 - k;
	LL h = (h1[l][i] - h1[l][i + (1 << k)] * pw[1 << (L - 1)] % mod + mod) % mod;
	return h == h2[k][i];
}

• Subtask 1: 13 / 13
• Subtask 2: 37 / 37
• Subtask 3: 17 / 17
• Subtask 4: 33 / 33