Add Freivalds' Algorithm for randomized matrix multiplication verification (#6340)

src/test/java/com/thealgorithms/randomized/RandomizedMatrixMultiplicationVerificationTest.java

@@ -0,0 +1,41 @@
+package com.thealgorithms.randomized;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class RandomizedMatrixMultiplicationVerificationTest {
+
+    @Test
+    void testCorrectMultiplication() {
+        int[][] a = {{1, 2}, {3, 4}};
+        int[][] b = {{5, 6}, {7, 8}};
+        int[][] c = {{19, 22}, {43, 50}};
+        assertTrue(RandomizedMatrixMultiplicationVerification.verify(a, b, c, 10));
+    }
+
+    @Test
+    void testIncorrectMultiplication() {
+        int[][] a = {{1, 2}, {3, 4}};
+        int[][] b = {{5, 6}, {7, 8}};
+        int[][] wrongC = {{20, 22}, {43, 51}};
+        assertFalse(RandomizedMatrixMultiplicationVerification.verify(a, b, wrongC, 10));
+    }
+
+    @Test
+    void testLargeMatrix() {
+        int size = 100;
+        int[][] a = new int[size][size];
+        int[][] b = new int[size][size];
+        int[][] c = new int[size][size];
+
+        for (int i = 0; i < size; i++) {
+            a[i][i] = 1;
+            b[i][i] = 1;
+            c[i][i] = 1;
+        }
+
+        assertTrue(RandomizedMatrixMultiplicationVerification.verify(a, b, c, 15));
+    }
+}