Preparing changes for btree add (defs + add stub).

current/algorithms/numbers-zig/numbers.zig

@@ -132,6 +132,38 @@ pub fn bipartition(arr: []u64, t1: u64, t2: u64, v: u64) u64 {
     return x2;
 }
 
-pub fn main() !void {
-    print("Hello World {}!!!\n", .{1});
+const BTree = struct {
+    n: u64,
+    values: []u64,
+    children: []?BTree,
+};
+
+pub fn BTree_Add(q: *BTree, v: u64) *BTree {
+    if (q.n <= q.values.len) {
+        const idx = bipartition(q.values, 0, q.n, v);
+        std.log.warn("Idx {}", idx);
+        const i: u64 = q.n;
+        while (i >= idx) {
+            q.values[idx + 1] = q.values[idx];
+            // TODO add here moving children pointers
+            idx -= 1;
+        }
+        q.n += 1;
+        q.values[idx] = v;
+        // TODO insert here element
+    }
+    return q;
+}
+
+pub fn main() !void {
+    const numbers = [_]u64{ 1, 2, 3 };
+    const numbers_sl: []const u64 = &numbers;
+    const children = [_]?BTree{ null, null, null, null };
+    const q = BTree{
+        .n = 0,
+        .values = numbers_sl,
+        .children = &children,
+    };
+    BTree_Add(q, 4);
+    print("Hello World {}!!!\n", .{q.values});
 }