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#include <cassert>
#include <cstdio>
#include "poszukiwania.h"
#include "message.h"
using namespace std;

typedef long long slng;

//#define DEBUGPRINT
//#define DEBUGPRINT2
//#define DEBUGASSERT

#ifdef DEBUGPRINT
#define DEBPRINT(...) fprintf(stderr, __VA_ARGS__)
#else
#define DEBPRINT(...)
#endif
#ifdef DEBUGPRINT2
#define DEBPRINT2(...) fprintf(stderr, __VA_ARGS__)
#else
#define DEBPRINT2(...)
#endif
#ifdef DEBUGASSERT
#define ASSERT(x) assert(x)
#else
#define ASSERT(x)
#endif

#define MAXNODES 107
#define NUMHASHES 3
int P[] = {
	1000000007, 1001000027, 1002000001, 1003000001, 1004000003,
	1005000047, 1006000001, 1007000009, 1008000013, 1009000009,
	1010000011, 1011000007, 1012000009, 1013000011, 1014000007,
};

int NODES, NODEID;
slng N, M;

struct HV {
	int v[NUMHASHES];
};
void hash_print(HV& h) {
#ifdef DEBPRINT
	int i;
	for (i = 0; i < NUMHASHES; i++)
		DEBPRINT("%d ", h.v[i]);
	DEBPRINT("\n");
#endif
}
bool hash_eq(HV& h1, HV& h2) {
	int i;
	for (i = 0; i < NUMHASHES; i++) {
		if (h1.v[i] != h2.v[i])
			return false;
	}
	return true;
}
void hash_add(HV& h, int r) {
	int i;
	for (i = 0; i < NUMHASHES; i++) {
		slng t = (slng) h.v[i] * P[i] + r;
		h.v[i] = t % P[i+1];
	}
}
void hash_addn(HV& h, HV&h2, int *rpow) {
	int i;
	for (i = 0; i < NUMHASHES; i++) {
		slng t = (slng) h.v[i] * rpow[i] + h2.v[i];
		h.v[i] = t % P[i+1];
	}
}
void hash_roll(HV& h, int *lpow, int l, int r) {
	int i;
	hash_add(h, r);
	for (i = 0; i < NUMHASHES; i++) {
		slng t = h.v[i] - ((slng) lpow[i] * l) % P[i+1];
		if (t < 0)
			t += P[i+1];
		h.v[i] = t;
	}
}
void hash_send(HV& h, int target) {
	int i;
	for (i = 0; i < NUMHASHES; i++) {
		PutInt(target, h.v[i]);
	}
	Send(target);
}
void hash_receive(HV&h, int source) {
	int i;
	Receive(source);
	for (i = 0; i < NUMHASHES; i++) {
		h.v[i] = GetInt(source);
	}
}

// n^p % mod;
int powmod(int n, int p, int mod) {
	slng res = 1;
	while (p>0) {
		if (p&1) {
			res = (res * n) % mod;
		}
		n = ((slng)n*n) % mod;
		p /= 2;
	}
	return res;
}
void primepow_arr(int *res, int p) {
	int i;
	for (i = 0; i < NUMHASHES; i++) {
		res[i] = powmod(P[i], p, P[i+1]);
	}
}
int text_segm_pow[NUMHASHES], pat_segm_pow[NUMHASHES], pat_len_pow[NUMHASHES];

HV pattern, pattern_frag[MAXNODES];
void hash_pattern() {
	int i;
	primepow_arr(pat_len_pow, M);
	if (M <= NODES) {
		int i;
		for (i = 1; i <= M; i++) {
			hash_add(pattern, SignalAt(i));
		}
		return;
	}
	int len = M / NODES;
	int start = NODEID * len + 1;
	DEBPRINT("Distributed hash_pattern [%d, %d)\n", start, start+len);
	for (i = start; i < start + len; i++) {
		hash_add(pattern_frag[NODEID], SignalAt(i));
	}
	for (i = 0; i < NODES; i++) {
		if (i != NODEID)
			hash_send(pattern_frag[NODEID], i);
	}
	primepow_arr(pat_segm_pow, len);
	for (i = 0; i < NODES; i++) {
		if (i != NODEID)
			hash_receive(pattern_frag[i], i);
		DEBPRINT("pattern_frag[%d]= ", i); hash_print(pattern_frag[i]);
		hash_addn(pattern, pattern_frag[i], pat_segm_pow);
	}
	DEBPRINT("hash_pattern tail [%d, %d]\n", NODES * len + 1, M);
	for (i = NODES * len + 1; i <= M; i++) {
		hash_add(pattern, SignalAt(i));
	}
}

HV text_segm[MAXNODES];
int text_segm_len;
void hash_textsegm() {
	int i;
	text_segm_len = N / NODES;
	int start = NODEID * text_segm_len + 1;
	if (text_segm_len == 0) {
		DEBPRINT("No hash_textsegm.\n");
		return;
	}
	for (i = start; i < start + text_segm_len; i++) {
		hash_add(text_segm[NODEID], SeqAt(i));
	}
	for (i = 0; i < NODES; i++) {
		if (i != NODEID)
			hash_send(text_segm[NODEID], i);
	}
	for (i = 0; i < NODES; i++) {
		if (i != NODEID)
			hash_receive(text_segm[i], i);
	}
	primepow_arr(text_segm_pow, text_segm_len);
}

HV text_rollhash;
int matches[MAXNODES];
void match() {
	int i;
	int len = (N - M + 1) / NODES;
	int start = NODEID * len + 1; // inclusive
	int end = start + len; // exclusive
	if (NODEID == NODES-1) {
		end = (N - M + 1) + 1;
	}
	if (start != end) {
		for (i = start; i < start + M; i++) {
			if (text_segm_len != 0 && i % text_segm_len == 1 && i + text_segm_len - 1 < start + M) {
				hash_addn(text_rollhash, text_segm[(i - 1) / text_segm_len], text_segm_pow);
				i += text_segm_len - 1;
			} else {
				hash_add(text_rollhash, SeqAt(i));
			}
		}
		for (i = start; i < end; i++) {
			hash_print(text_rollhash);
			if (hash_eq(text_rollhash, pattern)) {
				matches[NODEID]++;
			}
			if (i != end-1)
				hash_roll(text_rollhash, pat_len_pow, SeqAt(i), SeqAt(i + M));
		}
	}
	DEBPRINT("matches[%d]=%d\n", NODEID, matches[NODEID]);
	if (NODEID != 0) {
		DEBPRINT("Send to master\n");
		PutInt(0, matches[NODEID]);
		Send(0);
	} else /* NODEID == 0 */ {
		for (i = 1; i < NODES; i++) {
			DEBPRINT("Receive from %d\n", i);
			Receive(i);
			matches[0] += GetInt(i);
		}
		printf("%d\n", matches[0]);
	}
}

int main() {
	NODES = NumberOfNodes();
	NODEID = MyNodeId();
	M = SignalLength();
	N = SeqLength();
	hash_pattern();
	DEBPRINT("Hash pattern: "); hash_print(pattern);
	hash_textsegm();
	match();
	DEBPRINT("End\n");
	return 0;
}