Build heap done!

1. Modifying code so it's easy to test is always worth it!
Easier to identify the next concrete steps and carry them out!
2. Hand build a few arrays helped my understanding.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/test/BuildHeapTest.java b/src/test/BuildHeapTest.java
new file mode 100644
index 0000000..59b1711
--- /dev/null
+++ b/src/test/BuildHeapTest.java
@@ -0,0 +1,28 @@
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class BuildHeapTest {
+    @Test
+    void test1() {
+        int[] data = {5, 4, 3, 2, 1};
+        List<BuildHeap.Swap> swaps = BuildHeap.getSwaps(data);
+        assertEquals(3, swaps.size());
+        assertEquals(1, swaps.get(0).index1);
+        assertEquals(4, swaps.get(0).index2);
+        assertEquals(0, swaps.get(1).index1);
+        assertEquals(1, swaps.get(1).index2);
+        assertEquals(1, swaps.get(2).index1);
+        assertEquals(3, swaps.get(2).index2);
+    }
+
+    @Test
+    void test2() {
+        int[] data = {1, 2, 3, 4, 5};
+        List<BuildHeap.Swap> swaps = BuildHeap.getSwaps(data);
+        assertEquals(0, swaps.size());
+    }
+
+}
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