@@ -0,0 +1,42 @@
+import PolynomialHash from '../../cryptography/polynomial-hash/PolynomialHash';
+
+/**
+ * @param {string} text - Text that may contain the searchable word.
+ * @param {string} word - Word that is being searched in text.
+ * @return {number} - Position of the word in text.
+ */
+export default function rabinKarp(text, word) {
+  const hasher = new PolynomialHash();
+
+  // Calculate word hash that we will use for comparison with other substring hashes.
+  const wordHash = hasher.hash(word);
+
+  let prevFrame = null;
+  let currentFrameHash = null;
+
+  // Go through all substring of the text that may match.
+  for (let charIndex = 0; charIndex <= (text.length - word.length); charIndex += 1) {
+    const currentFrame = text.substring(charIndex, charIndex + word.length);
+
+    // Calculate the hash of current substring.
+    if (currentFrameHash === null) {
+      currentFrameHash = hasher.hash(currentFrame);
+    } else {
+      currentFrameHash = hasher.roll(currentFrameHash, prevFrame, currentFrame);
+    }
+
+    prevFrame = currentFrame;
+
+    // Compare the hash of current substring and seeking string.
+    // In case if hashes match let's make sure that substrings are equal.
+    // In case of hash collision the strings may not be equal.
+    if (
+      wordHash === currentFrameHash
+      && text.substr(charIndex, word.length) === word
+    ) {
+      return charIndex;
+    }
+  }
+
+  return -1;
+}