Add Fisher-Yates schuffle

1 files changed, 13 insertions, 0 deletions

diff --git a/utils.go b/utils.go
index 513786c..fe17650 100644
--- a/utils.go
+++ b/utils.go
@@ -1,5 +1,10 @@
 package main
 
+import (
+	"math/rand"
+	"sort"
+)
+
 // floor of log(x) (i.e MSB for positive integers)
 func Log(x int64) int64 {
 	var r int64 = 0
@@ -34,3 +39,11 @@ func Post(size int64, height int64, id int64) int64 {
 	}
 	return r
 }
+
+func Shuffle(data sort.Interface) {
+	var j int
+	for i := data.Len() - 1; i > 0; i-- {
+		j = rand.Intn(i + 1)
+		data.Swap(i, j)
+	}
+}