int KMPSearch(char *pat, char *txt, int M, int N){
int *longestPrefixSuffix = (int*)malloc(sizeof(int) * M);
int patIndex = 0;
computeLPSArray(pat, M, longestPrefixSuffix);
int txtIndex = 0;
while (txtIndex < N){
if (pat[patIndex] == txt[txtIndex]){
patIndex++;
txtIndex++;
}
if (patIndex == M){
return txtIndex - patIndex;
patIndex = longestPrefixSuffix[patIndex - 1];
}
else if (txtIndex < N && pat[patIndex] != txt[txtIndex]){
if (patIndex != 0)
patIndex = longestPrefixSuffix[patIndex - 1];
else
txtIndex = txtIndex + 1;
}
}
return -1;
}
int main() {
int count = 0;
char inputStringArray[] = "ABABDABACDABABDABACDABABCABAB";
char patArray[] = "ABABCABAB";
int pattLen = strlen(patArray);
int textLen = strlen(inputStringArray);
int matchPosition = 0; // index for inputStringArray[]
// create lps[] that will hold the longest prefix suffix
// values for pattern
int *lpsArray = (int *)calloc(pattLen, sizeof(int));
// Preprocess the pattern (calculate lps[] array)
computeLPSArray(patArray, pattLen, lpsArray);
for (count = 0; count < pattLen; count++)
printf("%d ", lpsArray[count]);
matchPosition = kmp_matcher(inputStringArray, textLen, patArray, pattLen, lpsArray);
if (matchPosition != -1)
printf("\nMatch found in the original input string at = %d\n", matchPosition);
else
printf("\nPattern Not Found The Original Input String\n");
free(lpsArray); // to avoid memory leak
}
void KMPSearch(char *pat, char *txt)
{
int M = strlen(pat);
int N = strlen(txt);
// create lps[] that will hold the longest prefix suffix values for pattern
int *lps = (int *)malloc(sizeof(int)*M);
int j = 0; // index for pat[]
// Preprocess the pattern (calculate lps[] array)
computeLPSArray(pat, M, lps);
int i = 0; // index for txt[]
while(i < N)
{
if(pat[j] == txt[i])
{
j++;
i++;
}
if (j == M)
{
printf("Found pattern at index %d \n", i-j);
j = lps[j-1];
}
// mismatch after j matches
else if(pat[j] != txt[i])
{
// Do not match lps[0..lps[j-1]] characters,
// they will match anyway
if(j != 0)
j = lps[j-1];
else
i = i+1;
}
}
free(lps); // to avoid memory leak
}
void FindCount(char *pat, char *txt, int *count)
{
int M = strlen(pat);
int N = strlen(txt);
int *lps = (int *)malloc(sizeof(int)*M);
int j = 0; // index for pat[]
// Preprocess the pattern (calculate lps[] array)
computeLPSArray(pat, M, lps);
int i = 0; // index for txt[]
while (i < N)
{
if (pat[j] == txt[i])
{
j++;
i++;
}
if (j == M)
{
//printf("Found pattern at index %d \n", i - j);
(*count)++;
j = lps[j - 1];
}
// mismatch after j matches
else if (i < N && pat[j] != txt[i])
{
// Do not match lps[0..lps[j-1]] characters,
// they will match anyway
if (j != 0)
j = lps[j - 1];
else
i = i + 1;
}
}
free(lps);
}
