Add golang implementation for insertion sort

Sorting/insertion_sort/insertion_sort.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+  "bufio"
+  "fmt"
+  "os"
+  "strconv"
+  "strings"
+)
+
+var reader *bufio.Reader = bufio.NewReader(os.Stdin)
+var writer *bufio.Writer = bufio.NewWriter(os.Stdout)
+
+func insertionSort(n int, arr []int) {
+  for j := 0; j < n; j++ {
+    // left to right 0:-->N
+    var val = arr[j]
+    i := j - 1
+    for ; i >= 0 && arr[i] > val; i-- {
+      // Scanning backward into the sorted portion A[0..j]
+      arr[i + 1] = arr[i]
+    }
+    arr[i + 1] = val
+  }
+}
+
+func readArray(reader *bufio.Reader, n int) []int {
+  str, _, err := reader.ReadLine()
+  if err != nil {
+    panic(err)
+  }
+
+  temp := strings.Split(string(str), " ")
+  arr := make([]int, n)
+
+  for i := 0; i < n; i++ {
+    arr[i], err = strconv.Atoi(temp[i])
+    if err != nil {
+      panic(err)
+    }
+  }
+
+  return arr
+}
+
+func main() {
+  defer writer.Flush()
+
+  var n int
+  fmt.Fscanf(reader, "%d\n", &n)
+  arr := readArray(reader, n)
+
+  fmt.Println("Before:", arr)
+  insertionSort(n, arr)
+  fmt.Println("After:", arr)
+}