Create KMP-Algorithm-Implementation.c

Author: santhosh-programmer

String-Matching/KMP-Algorithm-Implementation.c

@@ -0,0 +1,69 @@
+#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;
+}