LongestArithmeticSubsequenceTest.java

packagecom.thealgorithms.dynamicprogramming;

importstaticorg.junit.jupiter.api.Assertions.assertEquals;
importstaticorg.junit.jupiter.api.Assertions.assertThrows;

importjava.util.stream.Stream;
importorg.apache.commons.lang3.ArrayUtils;
importorg.junit.jupiter.api.Test;
importorg.junit.jupiter.params.ParameterizedTest;
importorg.junit.jupiter.params.provider.Arguments;
importorg.junit.jupiter.params.provider.MethodSource;

publicclassLongestArithmeticSubsequenceTest {
@ParameterizedTest
@MethodSource("provideTestCases")
voidtestGetLongestArithmeticSubsequenceLength(int[] nums, intexpected) {
assertEquals(expected, LongestArithmeticSubsequence.getLongestArithmeticSubsequenceLength(nums));
 }
@ParameterizedTest
@MethodSource("provideTestCases")
voidtestGetLongestArithmeticSubsequenceLengthReversedInput(int[] nums, intexpected) {
ArrayUtils.reverse(nums);
assertEquals(expected, LongestArithmeticSubsequence.getLongestArithmeticSubsequenceLength(nums));
 }

@Test
voidtestGetLongestArithmeticSubsequenceLengthThrowsForNullInput() {
assertThrows(IllegalArgumentException.class, () -> LongestArithmeticSubsequence.getLongestArithmeticSubsequenceLength(null));
 }

privatestaticStream<Arguments> provideTestCases() {
returnStream.of(Arguments.of(newint[] {3, 6, 9, 12, 15}, 5), Arguments.of(newint[] {1, 7, 10, 13, 14, 19}, 4), Arguments.of(newint[] {1, 2, 3, 4}, 4), Arguments.of(newint[] {}, 0), Arguments.of(newint[] {10}, 1), Arguments.of(newint[] {9, 4, 7, 2, 10}, 3),
Arguments.of(newint[] {1, 2, 2, 2, 2, 5}, 4));
 }
}