update

Task/Symmetric-difference/Aime/symmetric-difference.aime

@@ -0,0 +1,49 @@
+void
+show_sdiff(record u, record x)
+{
+    record r;
+    text s;
+
+    r_copy(r, u);
+
+    if (r_first(x, s)) {
+        do {
+            if (r_key(r, s)) {
+                r_delete(r, s);
+            } else {
+                r_p_integer(r, s, 0);
+            }
+        } while (r_greater(x, s, s));
+    }
+
+    if (r_first(r, s)) {
+        do {
+            o_text(s);
+            o_byte('\n');
+        } while (r_greater(r, s, s));
+    }
+}
+
+record
+new_set(...)
+{
+    integer i;
+    record r;
+
+    i = 0;
+    while (i < count()) {
+        r_p_integer(r, $i, 0);
+        i += 1;
+    }
+
+    return r;
+}
+
+integer
+main(void)
+{
+    show_sdiff(new_set("John", "Bob", "Mary", "Serena"),
+               new_set("Jim", "Mary", "John", "Bob"));
+
+    return 0;
+}