Data update

Task/Pick-random-element/DuckDB/pick-random-element.duckdb

@@ -0,0 +1,9 @@
+# PRN in range(0,n)
+create or replace function prn(n) as trunc(random() * n)::BIGINT;
+
+create or replace function list_random(lst) as
+  lst[ 1 + prn(length(lst)) ] ;
+
+## Example:
+select histogram( r )
+   from (select list_random( [1,2,3] ) as r from range(0,1000) _(n));

Task/Pick-random-element/Pluto/pick-random-element.pluto

@@ -0,0 +1,4 @@
+local ordinals = {"first", "second", "third", "fourth", "fifth", "sixth"}
+for _ = 1, 6 do
+    print(ordinals[math.random(1, #ordinals)])
+end

Task/Pick-random-element/Scheme/pick-random-element.scm

@@ -0,0 +1,6 @@
+; for Chicken Scheme
+(import (chicken random))
+
+(define (pick_random x)
+    (list-ref x (pseudo-random-integer (length x)))
+    )

Task/Pick-random-element/Tcl/pick-random-element-2.tcl

@@ -0,0 +1,79 @@
+# seed rng
+set seed [expr { srand([clock clicks]) }]
+
+# return a list of random selections of items from a list
+proc random_items { item_list {n 1} {dups no} } {
+
+    # use item_list in place as items
+    upvar 1 $item_list items
+
+    set result {}
+    set max    [llength $items]
+
+    if { $n > $max} {set n $max}
+
+    set count 0
+
+    while { $count < $n } {	
+
+   	    # random integer index 0..len-1
+	    set idx [expr { int(rand() * $max)} ]
+
+	    # pick item
+	    set item [lindex $items $idx]
+
+	    # check for dups
+	    if {$dups eq no} {
+	        set srch [lsearch $result $item]
+	        if {$srch > -1} { continue }
+	    }
+
+	    lappend result $item
+	    incr count   	
+    }
+    return  $result
+ }
+
+# randomize a list in place
+proc randomize {item_list} {
+    upvar 1 $item_list items
+    set len [llength $items]
+    set items [random_items items $len]
+}
+
+# return a new shuffled list
+proc shuffle {items} {
+    set len [llength $items]
+    return [random_items items $len]
+}
+
+# test cases
+
+set animals {
+    dog cat bird ant fish
+    horse pig cow snake mouse
+    whale worm bug spider deer
+    bee bear human gecko octopus
+}
+
+# 1 item default
+set guess [random_items animals]
+
+puts stdout "guess:  $guess \n"
+
+# in place shuffle
+randomize animals
+
+# list of 4 random items, no dups
+set A [random_items animals 4]
+set B [random_items animals 5]
+set C [random_items animals 6]
+
+set dashline [string repeat "-" 30]
+
+foreach a {$A $B $C} {
+   puts stdout $dashline
+   puts stdout "${a}"
+}
+
+puts stdout $dashline