KMP-Algorithm-Implementation.c

#include <stdio.h>
#include <string.h>
void computeLPSArray(char* pat, int M, int* lps);
void KMPSearch(char* pat, char* txt)
{
	int M = strlen(pat);
	int N = strlen(txt);
	int lps[M];
	computeLPSArray(pat, M, lps);
	int i = 0;
	int j = 0;
	while ((N - i) >= (M - j)) 
	{
		if (pat[j] == txt[i]) 
		{
			j++;
			i++;
		}
		if (j == M) 
		{
			printf("%d ", i - j);
			j = lps[j - 1];
		}
		else if (i < N && pat[j] != txt[i]) 
		{
			if (j != 0)
				j = lps[j - 1];
			else
				i = i + 1;
		}
	}
	printf("\n");
	for(int i=0;i<M;i++)
	printf("%d ",lps[i]);
}
void computeLPSArray(char* pat, int M, int* lps)
{
	int len = 0;
	lps[0] = 0;
	int i = 1;
	while (i < M) 
	{
		if (pat[i] == pat[len]) 
		{
			len++;
			lps[i] = len;
			i++;
		}
		else
		{
			if (len != 0)
			len = lps[len - 1];
			else
			{
				lps[i] = 0;
				i++;
			}
		}
	}
}
int main()
{
    char txt[50];
    char pat[50];
    scanf("%[^\n]s",txt);
    scanf("%s",pat);
	KMPSearch(pat, txt);
	return 0;
}