chore: add hackerrank solutions

hacker-rank/counting-sort/main.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+    "bufio"
+    "fmt"
+    "io"
+    "os"
+    "strconv"
+    "strings"
+)
+
+/*
+ * Complete the 'countingSort' function below.
+ *
+ * The function is expected to return an INTEGER_ARRAY.
+ * The function accepts INTEGER_ARRAY arr as parameter.
+ */
+
+func countingSort(arr []int32) []int32 {
+    freq := make([]int32, 100)
+    for _, i := range arr {
+        freq[i]++
+    }
+    return freq
+}
+
+func main() {
+    reader := bufio.NewReaderSize(os.Stdin, 16 * 1024 * 1024)
+
+    stdout, err := os.Create(os.Getenv("OUTPUT_PATH"))
+    checkError(err)
+
+    defer stdout.Close()
+
+    writer := bufio.NewWriterSize(stdout, 16 * 1024 * 1024)
+
+    nTemp, err := strconv.ParseInt(strings.TrimSpace(readLine(reader)), 10, 64)
+    checkError(err)
+    n := int32(nTemp)
+
+    arrTemp := strings.Split(strings.TrimSpace(readLine(reader)), " ")
+
+    var arr []int32
+
+    for i := 0; i < int(n); i++ {
+        arrItemTemp, err := strconv.ParseInt(arrTemp[i], 10, 64)
+        checkError(err)
+        arrItem := int32(arrItemTemp)
+        arr = append(arr, arrItem)
+    }
+
+    result := countingSort(arr)
+
+    for i, resultItem := range result {
+        fmt.Fprintf(writer, "%d", resultItem)
+
+        if i != len(result) - 1 {
+            fmt.Fprintf(writer, " ")
+        }
+    }
+
+    fmt.Fprintf(writer, "\n")
+
+    writer.Flush()
+}
+
+func readLine(reader *bufio.Reader) string {
+    str, _, err := reader.ReadLine()
+    if err == io.EOF {
+        return ""
+    }
+
+    return strings.TrimRight(string(str), "\r\n")
+}
+
+func checkError(err error) {
+    if err != nil {
+        panic(err)
+    }
+}