package com.thealgorithms.stacks; import static org.junit.jupiter.api.Assertions.assertEquals; import java.util.stream.Stream; import org.junit.jupiter.params.ParameterizedTest; import org.junit.jupiter.params.provider.Arguments; import org.junit.jupiter.params.provider.MethodSource; public class CelebrityFinderTest { @ParameterizedTest @MethodSource("providePartyMatrices") public void testCelebrityFinder(int[][] party, int expected) { assertEquals(expected, CelebrityFinder.findCelebrity(party)); } private static Stream providePartyMatrices() { return Stream.of( // Test case 1: Celebrity exists Arguments.of(new int[][] {{0, 1, 1}, {0, 0, 1}, {0, 0, 0}}, 2), // Test case 2: No celebrity Arguments.of(new int[][] {{0, 1, 0}, {1, 0, 1}, {1, 1, 0}}, -1), // Test case 3: Everyone knows each other, no celebrity Arguments.of(new int[][] {{0, 1, 1}, {1, 0, 1}, {1, 1, 0}}, -1), // Test case 4: Single person, they are trivially a celebrity Arguments.of(new int[][] {{0}}, 0), // Test case 5: All know the last person, and they know no one Arguments.of(new int[][] {{0, 1, 1, 1}, {0, 0, 1, 1}, {0, 0, 0, 1}, {0, 0, 0, 0}}, 3), // Test case 6: Larger party with no celebrity Arguments.of(new int[][] {{0, 1, 1, 0}, {1, 0, 0, 1}, {0, 1, 0, 1}, {1, 1, 1, 0}}, -1), // Test case 7: Celebrity at the start of the matrix Arguments.of(new int[][] {{0, 0, 0}, {1, 0, 1}, {1, 1, 0}}, 0)); } }