Data update

Task/Order-by-pair-comparisons/Pluto/order-by-pair-comparisons.pluto

@@ -0,0 +1,37 @@
+require "io2"
+local fmt = require "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.
+local function insort_right(a, x, q)
+    local lo = 1
+    local hi = #a + 1
+    local yn = "ynYN":split("")
+    while lo < hi do
+        local mid = (lo + hi) // 2
+        ++q
+        local prompt = string.format("%2d: Is %6s less than %6s ? y/n: ", q, x, a[mid])
+        local less = string.lower(io.readOpt(prompt, yn)) == "y"
+        if less then
+            hi = mid
+        else
+            lo = mid + 1
+        end
+     end
+     a:insert(lo, x)
+     return q
+end
+
+local function order(items)
+    local ordered = {}
+    local q = 0
+    for items as item do
+        q = insort_right(ordered, item, q)
+    end
+    return ordered
+end
+
+local items = "violet red green indigo blue yellow orange":split(" ")
+local ordered = order(items)
+print("\nThe colors of the rainbow, in sorted order, are:")
+fmt.lprint(ordered)

Task/Order-by-pair-comparisons/Prolog/order-by-pair-comparisons-1.pro

@@ -0,0 +1,12 @@
+ask_sort(List, Sorted) :- predsort(ask, List, Sorted).
+
+ask(Cmp, Left, Right) :-
+    format("Comparing ~w with ~w:   ", [Left, Right]),
+    get_single_char(Cmp0),
+    char_code(Cmp1, Cmp0),
+    (   memberchk(Cmp1, [<, =, >])
+    ->  Cmp = Cmp1,
+        writeln(Cmp1)
+    ;   format("Please answer <, = or >."),
+        ask(Cmp, Left, Right)
+    ).

Task/Order-by-pair-comparisons/Prolog/order-by-pair-comparisons-2.pro

@@ -0,0 +1,15 @@
+?- ask_sort(["violet", "red", "green", "indigo", "blue", "yellow", "orange"], Sorted).
+Comparing red with green:   <
+Comparing violet with red:   >
+Comparing violet with green:   >
+Comparing indigo with blue:   >
+Comparing yellow with orange:   >
+Comparing blue with orange:   >
+Comparing blue with yellow:   >
+Comparing red with orange:   <
+Comparing green with orange:   >
+Comparing green with yellow:   >
+Comparing green with blue:   <
+Comparing violet with blue:   >
+Comparing violet with indigo:   >
+Sorted = ["red", "orange", "yellow", "green", "blue", "indigo", "violet"].