src/catar/binary_search_tree.rs: add regression tests and fix one bug

src/catar/binary_search_tree.rs

@@ -47,7 +47,7 @@ fn copy_binary_search_tree_inner<F:  FnMut(usize, usize)>(
     (copy_func)(o+m, i);
 
     if m > 0 {
-        copy_binary_search_tree_inner(copy_func, m, 0, e-1, i*2+1);
+        copy_binary_search_tree_inner(copy_func, m, o, e-1, i*2+1);
     }
 
     if (m + 1) < n {
@@ -63,3 +63,47 @@ pub fn copy_binary_search_tree<F:  FnMut(usize, usize)>(
     let e = (64 - n.leading_zeros() - 1) as usize; // fast log2(n)
     copy_binary_search_tree_inner(&mut copy_func, n, 0, e, 0);
 }
+
+
+#[test]
+fn test_binary_search_tree() {
+
+    fn run_test(len: usize) -> Vec<usize> {
+
+        const MARKER: usize = 0xfffffff;
+        let mut output = vec![];
+        for i in 0..len { output.push(MARKER); }
+        copy_binary_search_tree(len, |s, d| {
+            assert!(output[d] == MARKER);
+            output[d] = s;
+        });
+        if len < 32 { println!("GOT:{}:{:?}", len, output); }
+        for i in 0..len {
+            assert!(output[i] != MARKER);
+        }
+        output
+    }
+
+    assert!(run_test(0).len() == 0);
+    assert!(run_test(1) == [0]);
+    assert!(run_test(2) == [1,0]);
+    assert!(run_test(3) == [1,0,2]);
+    assert!(run_test(4) == [2,1,3,0]);
+    assert!(run_test(5) == [3,1,4,0,2]);
+    assert!(run_test(6) == [3,1,5,0,2,4]);
+    assert!(run_test(7) == [3,1,5,0,2,4,6]);
+    assert!(run_test(8) == [4,2,6,1,3,5,7,0]);
+    assert!(run_test(9) == [5,3,7,1,4,6,8,0,2]);
+    assert!(run_test(10) == [6,3,8,1,5,7,9,0,2,4]);
+    assert!(run_test(11) == [7,3,9,1,5,8,10,0,2,4,6]);
+    assert!(run_test(12) == [7,3,10,1,5,9,11,0,2,4,6,8]);
+    assert!(run_test(13) == [7,3,11,1,5,9,12,0,2,4,6,8,10]);
+    assert!(run_test(14) == [7,3,11,1,5,9,13,0,2,4,6,8,10,12]);
+    assert!(run_test(15) == [7,3,11,1,5,9,13,0,2,4,6,8,10,12,14]);
+    assert!(run_test(16) == [8,4,12,2,6,10,14,1,3,5,7,9,11,13,15,0]);
+    assert!(run_test(17) == [9,5,13,3,7,11,15,1,4,6,8,10,12,14,16,0,2]);
+
+    for len in 18..1000 {
+        run_test(len);
+    }
+}