Create kmp.cpp

String/kmp.cpp

@@ -0,0 +1,29 @@
+#include <string>
+#include <vector>
+using namespace std;
+
+int KMP(string &S, string &T) {
+	// Generate KMP table
+	vector<int> F(T.length() + 1, 0);
+	F[0] = -1;
+	for (int i = 0; i < T.length(); i++) {
+		F[i + 1] = F[i];
+		while (F[i + 1] > -1 && T[i] != T[F[i + 1]]) F[i + 1] = F[F[i + 1]];
+		F[i + 1]++;
+	}
+
+	// Search
+	int i = 0, j = 0;
+	while (i < S.length()) {
+		if (S[i] == T[j]) {
+			i++, j++;
+			if (j == T.length()) return i - j; // Found match
+		}
+		else {
+			j = F[j];
+			if (j < 0) i++, j++;
+		}
+	}
+
+	return -1; // Match not found
+}