Java/src/test/java/com/thealgorithms/maths/KrishnamurthyNumberTest.java at master · Drive-for-Java/Java · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
package com.thealgorithms.maths;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;

/**
 * Unit tests for the {@link KrishnamurthyNumber} class.
 */
class KrishnamurthyNumberTest {

    /**
     * Test with known Krishnamurthy number 145.
     * 1! + 4! + 5! = 1 + 24 + 120 = 145
     */
    @Test
    void testIsKrishnamurthyWith145() {
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(145));
    }

    /**
     * Test with a number that is not a Krishnamurthy number.
     */
    @Test
    void testIsKrishnamurthyWithNonKrishnamurthyNumber() {
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(123));
    }

    /**
     * Test with zero, which is not a Krishnamurthy number.
     */
    @Test
    void testIsKrishnamurthyWithZero() {
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(0));
    }

    /**
     * Test with negative numbers, which cannot be Krishnamurthy numbers.
     */
    @Test
    void testIsKrishnamurthyWithNegativeNumbers() {
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(-1));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(-145));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(-100));
    }

    /**
     * Test with single-digit Krishnamurthy numbers.
     * 1! = 1 and 2! = 2, so both 1 and 2 are Krishnamurthy numbers.
     */
    @Test
    void testIsKrishnamurthyWithSingleDigitKrishnamurthyNumbers() {
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(1));
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(2));
    }

    /**
     * Test with single-digit numbers that are not Krishnamurthy numbers.
     */
    @Test
    void testIsKrishnamurthyWithSingleDigitNonKrishnamurthyNumbers() {
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(3));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(4));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(5));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(6));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(7));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(8));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(9));
    }

    /**
     * Test with the largest Krishnamurthy number: 40585.
     * 4! + 0! + 5! + 8! + 5! = 24 + 1 + 120 + 40320 + 120 = 40585
     */
    @Test
    void testIsKrishnamurthyWithLargestKrishnamurthyNumber() {
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(40585));
    }

    /**
     * Test with various non-Krishnamurthy numbers.
     */
    @Test
    void testIsKrishnamurthyWithVariousNonKrishnamurthyNumbers() {
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(10));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(50));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(100));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(144));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(146));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(150));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(200));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(999));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(1000));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(40584));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(40586));
    }

    /**
     * Test with numbers close to known Krishnamurthy numbers.
     */
    @Test
    void testIsKrishnamurthyWithNumbersCloseToKrishnamurthy() {
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(144));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(146));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(40584));
        assertFalse(KrishnamurthyNumber.isKrishnamurthy(40586));
    }

    /**
     * Test with all known Krishnamurthy numbers in base 10.
     */
    @Test
    void testAllKnownKrishnamurthyNumbers() {
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(1));
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(2));
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(145));
        assertTrue(KrishnamurthyNumber.isKrishnamurthy(40585));
    }
}