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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
#include <vector>
#include "message.h"
#include "poszukiwania.h"

using namespace std;

int* pi = 0;
int psize;

#if 0

int *compute_prefix_function()
{
	int k = -1;
	int i = 1;
	int *pi = (int*) malloc(sizeof(int)*psize);
	if (!pi)
		return NULL;

	pi[0] = k;
	for (i = 1; i < psize; i++) {
		while (k > -1 && SignalAt(k+2) != SignalAt(i+1))
			k = pi[k];
		if (SignalAt(i+1) == SignalAt(k+2))
			k++;
		pi[i] = k;
	}
	return pi;
}

int kmp(int start, int tsize)
{
	int i;
	int k = -1;
	int count = 0;
	for (i = 0; i < tsize; i++) {
		while (k > -1 && SignalAt(k+2) != SeqAt(i+1+start))
			k = pi[k];
		if (SeqAt(i+1+start) == SignalAt(k+2))
			k++;
		if (k == psize - 1) {
			++count;
			k = pi[k];
			continue;
		}
	}
	return count;
}

#else

int M;

int kmp(int start, int size)
{
	int count = 0;
	int N = size;

    int j  = 0;  // index for pat[]
 
    int i = 0;  // index for txt[]
    while (i < N)
    {
      if (SignalAt(j+1) == SeqAt(i+1))
      {
        j++;
        i++;
      }
 
      if (j == M)
      {
        j = pi[j-1];
		++count;
      }
 
      // mismatch after j matches
      else if (i < N && SignalAt(j+1) != SeqAt(i+1))
      {
        // Do not match lps[0..lps[j-1]] characters,
        // they will match anyway
        if (j != 0)
         j = pi[j-1];
        else
         i = i+1;
      }
    }
    return count;
}
 
int *compute_prefix_function()
{
	M = SignalLength();
	int *pi = (int*) malloc(sizeof(int)*psize);

    int len = 0;  // lenght of the previous longest prefix suffix
    int i;
 
    pi[0] = 0; // lps[0] is always 0
    i = 1;
 
    // the loop calculates lps[i] for i = 1 to M-1
    while (i < M)
    {
       if (SignalAt(i+1) == SignalAt(len+1))
       {
         len++;
         pi[i] = len;
         i++;
       }
       else // (pat[i] != pat[len])
       {
         if (len != 0)
         {
           // This is tricky. Consider the example AAACAAAA and i = 7.
           len = pi[len-1];
 
           // Also, note that we do not increment i here
         }
         else // if (len == 0)
         {
           pi[i] = 0;
           i++;
         }
       }
    }
	return pi;
}

#endif

int main()
{
	psize = SignalLength();
	pi = compute_prefix_function();

	const int n = SeqLength() - SignalLength() + 1;
	const int myStart = MyNodeId() * n / NumberOfNodes();
	const int myEnd = ( MyNodeId() + 1 ) * n / NumberOfNodes();
	
	int start = myStart;
	int size = myEnd - myStart + SignalLength() - 1;
	int count = kmp( start, size );
	
	if (!MyNodeId())
	{
		for ( int i = 1; i < NumberOfNodes(); ++i)
		{
			Receive( i );
			count += GetInt( i );
		}
		cout << count;
	}
	else
	{
		PutInt( 0, count );
		Send( 0 );
	}

	return 0;
}