#154 make change

src/MakeChange154/Change.java

@@ -0,0 +1,28 @@
+package MakeChange154;
+
+import java.util.*;
+
+public class Change {
+
+    private Vector<Integer> units;
+
+    public Change(Vector<Integer> units) {
+        this.units = units;
+    }
+
+    public Vector<Integer> makeChange(Integer money) {
+        Vector<Integer> result = new Vector<Integer>();
+
+        Integer remainMoney = money;
+
+        for (Integer unit : units) {
+            for (int num = 1; num <= remainMoney / unit; num++) {
+                result.add(unit);
+            }
+            remainMoney -= remainMoney / unit * unit;
+            if (remainMoney <= 0) break;
+        }
+
+        return result;
+    }
+}

test/MakeChange154Test/ChangeTest.java

@@ -0,0 +1,63 @@
+package MakeChange154Test;
+
+import MakeChange154.*;
+import org.testng.annotations.*;
+
+import java.util.*;
+
+import static junit.framework.Assert.*;
+
+public class ChangeTest {
+
+    private Change change;
+
+    @BeforeClass
+    private void setup_change() {
+        Vector<Integer> moneyUnits = new Vector<Integer>();
+        moneyUnits.add(25);
+        moneyUnits.add(10);
+        moneyUnits.add(5);
+        moneyUnits.add(1);
+
+        change = new Change(moneyUnits);
+    }
+
+    @Test
+    public void should_return_1_for_change_1() {
+        Vector<Integer> expectedChanges = new Vector<Integer>();
+        expectedChanges.add(1);
+
+        assertVectorIntegerEquals(expectedChanges, change.makeChange(1));
+    }
+
+    @Test
+    public void should_return_5_1_for_change_6() {
+        Vector<Integer> expectedChanges = new Vector<Integer>();
+        expectedChanges.add(5);
+        expectedChanges.add(1);
+
+        assertVectorIntegerEquals(expectedChanges, change.makeChange(6));
+    }
+
+    @Test
+    public void should_return_25_10_10_1_1_1_1_for_change_49() {
+        Vector<Integer> expectedChanges = new Vector<Integer>();
+        expectedChanges.add(25);
+        expectedChanges.add(10);
+        expectedChanges.add(10);
+        expectedChanges.add(1);
+        expectedChanges.add(1);
+        expectedChanges.add(1);
+        expectedChanges.add(1);
+
+        assertVectorIntegerEquals(expectedChanges, change.makeChange(49));
+    }
+
+    private void assertVectorIntegerEquals(Vector<Integer> expected, Vector<Integer> actual) {
+        assertEquals("length not equal", expected.size(), actual.size());
+
+        for (int i = 0; i < expected.size(); i++) {
+            assertEquals(i + "th value not equal", expected.get(i), actual.get(i));
+        }
+    }
+}