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authorMistivia <i@mistivia.com>2025-11-02 15:27:18 +0800
committerMistivia <i@mistivia.com>2025-11-02 15:27:18 +0800
commite9c24f4af7ed56760f6db7941827d09f6db9020b (patch)
tree62128c43b883ce5e3148113350978755779bb5de /teleirc/matterbridge/vendor/modernc.org/mathutil/permute.go
parent58d5e7cfda4781d8a57ec52aefd02983835c301a (diff)
add matterbridge
Diffstat (limited to 'teleirc/matterbridge/vendor/modernc.org/mathutil/permute.go')
-rw-r--r--teleirc/matterbridge/vendor/modernc.org/mathutil/permute.go39
1 files changed, 39 insertions, 0 deletions
diff --git a/teleirc/matterbridge/vendor/modernc.org/mathutil/permute.go b/teleirc/matterbridge/vendor/modernc.org/mathutil/permute.go
new file mode 100644
index 0000000..e2ff3d6
--- /dev/null
+++ b/teleirc/matterbridge/vendor/modernc.org/mathutil/permute.go
@@ -0,0 +1,39 @@
+// Copyright (c) 2014 The mathutil Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mathutil // import "modernc.org/mathutil"
+
+import (
+ "sort"
+)
+
+// PermutationFirst generates the first permutation of data.
+func PermutationFirst(data sort.Interface) {
+ sort.Sort(data)
+}
+
+// PermutationNext generates the next permutation of data if possible and
+// return true. Return false if there is no more permutation left. Based on
+// the algorithm described here:
+// http://en.wikipedia.org/wiki/Permutation#Generation_in_lexicographic_order
+func PermutationNext(data sort.Interface) bool {
+ var k, l int
+ for k = data.Len() - 2; ; k-- { // 1.
+ if k < 0 {
+ return false
+ }
+
+ if data.Less(k, k+1) {
+ break
+ }
+ }
+ for l = data.Len() - 1; !data.Less(k, l); l-- { // 2.
+ }
+ data.Swap(k, l) // 3.
+ for i, j := k+1, data.Len()-1; i < j; i++ { // 4.
+ data.Swap(i, j)
+ j--
+ }
+ return true
+}