2016 Update

Task/Nth/Factor/nth.factor

@@ -0,0 +1,28 @@
+USING: math kernel combinators math.ranges math.parser
+    sequences io ;
+IN: nth
+
+: tens-digit ( n -- n ) 10 [ /i ] [ mod ] bi ;
+
+: teens? ( n -- ? ) tens-digit 1 = ;
+
+: non-teen-suffix ( n -- str )
+    10 mod {
+        { 1 [ "st" ] }
+        { 2 [ "nd" ] }
+        { 3 [ "rd" ] }
+        [ drop "th" ]
+    } case ;
+
+: ordinal-suffix ( n -- str )
+    dup teens? [ drop 0 ] when non-teen-suffix ;
+
+: join-suffix ( n -- str ) dup ordinal-suffix
+    [ number>string ] dip append ;
+
+: main ( -- )
+    0 25 250 265 1000 1025 [ [a,b] ] 2tri@
+    [ [ join-suffix ] map ] tri@
+    [ [ bl ] [ write ] interleave nl ] tri@ ;
+
+MAIN: main