Generalize NthUglyNumber (#4209)

src/test/java/com/thealgorithms/maths/NthUglyNumberTest.java

@@ -0,0 +1,87 @@
+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.HashMap;
+
+import org.junit.jupiter.api.Test;
+
+public class NthUglyNumberTest {
+    @Test
+    public void testGetWithNewObject() {
+        HashMap<Integer, Long> testCases = new HashMap<>();
+        testCases.put(0, 1L);
+        testCases.put(1, 2L);
+        testCases.put(2, 3L);
+        testCases.put(3, 4L);
+        testCases.put(4, 5L);
+        testCases.put(5, 6L);
+        testCases.put(9, 12L);
+        testCases.put(19, 36L);
+        testCases.put(52, 270L);
+        testCases.put(1078, 84934656L);
+        testCases.put(1963, 6973568802L);
+
+        for (final var tc : testCases.entrySet()) {
+            var uglyNumbers = new NthUglyNumber(new int[] {2, 3, 5});
+            assertEquals(uglyNumbers.get(tc.getKey()), tc.getValue());
+
+            var otherUglyNumbers = new NthUglyNumber(new int[] {5, 25, 6, 2, 3, 5});
+            assertEquals(otherUglyNumbers.get(tc.getKey()), tc.getValue());
+        }
+    }
+
+    @Test
+    public void testGetWithSameObject() {
+        HashMap<Integer, Long> testCases = new HashMap<>();
+        testCases.put(0, 1L);
+        testCases.put(1, 2L);
+        testCases.put(2, 3L);
+        testCases.put(3, 4L);
+        testCases.put(4, 5L);
+        testCases.put(5, 6L);
+        testCases.put(6, 7L);
+        testCases.put(1499, 1984500L);
+        testCases.put(1572, 2449440L);
+        testCases.put(1658, 3072000L);
+        testCases.put(6625, 4300800000L);
+
+        var uglyNumbers = new NthUglyNumber(new int[] {7, 2, 5, 3});
+        for (final var tc : testCases.entrySet()) {
+            assertEquals(uglyNumbers.get(tc.getKey()), tc.getValue());
+        }
+        
+        assertEquals(uglyNumbers.get(999), 385875);
+    }
+
+    @Test
+    public void testGetWithBase1() {
+        var uglyNumbers = new NthUglyNumber(new int[] {1});
+        assertEquals(uglyNumbers.get(10), 1);
+    }
+
+    @Test
+    public void testGetWithBase2() {
+        var uglyNumbers = new NthUglyNumber(new int[] {2});
+        assertEquals(uglyNumbers.get(5), 32);
+    }
+
+
+    @Test
+    public void testGetThrowsAnErrorForNegativeInput() {
+        var uglyNumbers = new NthUglyNumber(new int[] {1, 2});
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> uglyNumbers.get(-1)
+        );
+    }
+
+    @Test
+    public void testConstructorThrowsAnErrorForEmptyInput() {
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> new NthUglyNumber(new int[] {})
+        );
+    }
+}