Data update

Task/Permutations/AWK/permutations-3.awk

@@ -0,0 +1,23 @@
+function permute(l, k,   i, s) {
+  if (k == length(l)) {
+    show(s)
+    return
+  }
+  for (i=k; i <= length(l); ++i) {
+    swap(l, i, k)
+    permute(l, k+1)
+    swap(l, k, i)
+  }
+}
+function swap(l, i, k,    t) {
+  t = l[i]
+  l[i] = l[k]
+  l[k] = t
+}
+BEGIN {
+  n = 3                               # default
+  if (ARGC > 1) n = ARGV[1]           # number may be given as parameter
+  for (i=1; i <=n; ++i)
+    l[i] = i
+  permute(l, 1)
+  }