Add StockProfitCalculator (#5793)

src/test/java/com/thealgorithms/greedyalgorithms/StockProfitCalculatorTest.java

@@ -0,0 +1,21 @@
+package com.thealgorithms.greedyalgorithms;
+
+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 StockProfitCalculatorTest {
+
+    @ParameterizedTest
+    @MethodSource("provideTestCases")
+    public void testMaxProfit(int[] prices, int expected) {
+        assertEquals(expected, StockProfitCalculator.maxProfit(prices));
+    }
+
+    private static Stream<Arguments> provideTestCases() {
+        return Stream.of(Arguments.of(new int[] {7, 1, 5, 3, 6, 4}, 5), Arguments.of(new int[] {7, 6, 4, 3, 1}, 0), Arguments.of(new int[] {5, 5, 5, 5, 5}, 0), Arguments.of(new int[] {10}, 0), Arguments.of(new int[] {1, 5}, 4), Arguments.of(new int[] {2, 4, 1, 3, 7, 5}, 6));
+    }
+}