Create Rabin-KarpAlgorithm.cpp

Rabin-KarpAlgorithm.cpp

@@ -0,0 +1,52 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+void search(char pat[], char txt[], int q) 
+{ 
+	int M = strlen(pat); 
+	int N = strlen(txt); 
+	int i, j, p = 0,t = 0, h = 1;
+
+	for (i = 0; i < M - 1; i++) // The value of h would be "pow(d, M-1)%q" 
+		h = (h * d) % q; 
+
+	// we Calculate the hash value of pattern and first window of text 
+	for (i = 0; i < M; i++) { 
+		p = (d * p + pat[i]) % q; 
+		t = (d * t + txt[i]) % q; 
+	} 
+
+	//  we slide text one by one in the pattern
+	for (i = 0; i <= N - M; i++) { 
+
+		if (p == t) { 	//If the hash values match then only check for characters on by one 
+			/* Check for characters one by one */
+			for (j = 0; j < M; j++) { 
+				if (txt[i + j] != pat[j]) 
+					break; 
+			} 
+
+
+			if (j == M) // if p == t and pat[0...M-1] = txt[i, i+1, ...i+M-1] 
+				printf("Pattern found at index %d \n", i); 
+		} 
+
+		if (i < N - M) { // now we Calculate hash value for next window of text:
+			t = (d * (t - txt[i] * h) + txt[i + M]) % q; 
+
+
+			if (t < 0) //if we get negative then 
+				t = (t + q); 
+		} 
+	} 
+} 
+
+int main() 
+{ 
+	char txt[] = "ANOM is learning"; 
+	char pat[] = "ANOM"; 
+	int q = 101; 
+  int d=256;
+	search(pat, txt, q); 
+	return 0; 
+}