Data commit

Task/Order-by-pair-comparisons/Wren/order-by-pair-comparisons.wren

@@ -0,0 +1,36 @@
+import "/ioutil" for Input
+import "/fmt" for Fmt
+
+// Inserts item x in list a, and keeps it sorted assuming a is already sorted.
+// If x is already in a, inserts it to the right of the rightmost x.
+var insortRight = Fn.new{ |a, x, q|
+    var lo = 0
+    var hi = a.count
+    while (lo < hi) {
+        var mid = ((lo + hi)/2).floor
+        q = q + 1
+        var prompt = Fmt.swrite("$2d: Is $6s less than $6s ? y/n: ", q, x, a[mid])
+        var less = Input.option(prompt, "yn") == "y"
+        if (less) {
+            hi = mid
+        } else {
+            lo = mid + 1
+        }
+     }
+     a.insert(lo, x)
+     return q
+}
+
+var order = Fn.new { |items|
+    var ordered = []
+    var q = 0
+    for (item in items) {
+        q = insortRight.call(ordered, item, q)
+    }
+    return ordered
+}
+
+var items = "violet red green indigo blue yellow orange".split(" ")
+var ordered = order.call(items)
+System.print("\nThe colors of the rainbow, in sorted order, are:")
+System.print(ordered)