Merge pull request #168 from ashishkrishan1995/master

radix sort in golang

Sorting/Radix Sort/golang/radixsort.go

@@ -0,0 +1,49 @@
+// Radix Sort in Golang
+package main
+
+import (
+    "bytes"
+    "encoding/binary"  
+    "fmt"
+)
+
+const digit = 4
+const maxbit = -1 << 31
+
+
+func main() {
+
+    var data = []int32{421, 15, -175, 90, -2, 214, -52, -166}
+    fmt.Println("\n--- Unsorted --- \n\n", data)
+    radixsort(data)
+    fmt.Println("\n--- Sorted ---\n\n", data, "\n")
+} 
+
+func radixsort(data []int32) {
+    buf := bytes.NewBuffer(nil)
+    ds := make([][]byte, len(data))
+    for i, e := range data {
+        binary.Write(buf, binary.LittleEndian, e^maxbit)
+        b := make([]byte, digit)
+        buf.Read(b)
+        ds[i] = b
+    }
+    countingSort := make([][][]byte, 256)
+    for i := 0; i < digit; i++ {
+        for _, b := range ds {
+            countingSort[b[i]] = append(countingSort[b[i]], b)
+        }
+        j := 0
+        for k, bs := range countingSort {
+            copy(ds[j:], bs)
+            j += len(bs)
+            countingSort[k] = bs[:0]
+        }
+    }   
+    var w int32
+    for i, b := range ds {
+        buf.Write(b)
+        binary.Read(buf, binary.LittleEndian, &w)
+        data[i] = w^maxbit
+    }   
+}