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authorShinya Sato <shinnya.sato@gmail.com>2021-09-24 16:42:54 +0900
committerShinya Sato <shinnya.sato@gmail.com>2021-09-24 16:42:54 +0900
commit6b3075d90d945d5e7e8fd4d28284ffd99dbeb82e (patch)
tree4d9e58166e36452bc3a19172d9cfb7a245f996b0 /sample/qsort.in
parentdd62122ee43d2c388fb96518eaa527976fddfc38 (diff)
downloadinpla-6b3075d90d945d5e7e8fd4d28284ffd99dbeb82e.tar.gz
inpla-6b3075d90d945d5e7e8fd4d28284ffd99dbeb82e.zip
v0.4.1
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+// Quick sort
+
+// Rules
+qsort(ret) >< [] => ret~[];
+qsort(ret) >< (int x):xs =>
+ part(x, left, right)~xs,
+ qsort(cntl)~left, qsort(cntr)~right,
+ Append(ret, x:cntl)~cntr;
+
+// Note: `Append' is implemented as built-in.
+// Append(ret, a)~b --> ret ~ b@a
+
+part(int x, a, b) >< [] => a~[], b~[];
+part(int x, a, b) >< (int y):ys
+| y<x => b~(y:cnt), part(x, a, cnt)~ys
+| _ => a~(y:cnt), part(x, cnt, b)~ys;
+
+
+// Nets
+qsort(ret)~[3,6,1,9,2];
+ret; \ No newline at end of file