Problem Solving : Golang | Left Rotation - Hackerrank.go

Problem Solving : Golang | Left Rotation - Hackerrank.go

package main

import (
    "bufio"
    "fmt"
    "io"
    "os"
    "strconv"
    "strings"
)

/*
 * Complete the 'rotateLeft' function below.
 *
 * The function is expected to return an INTEGER_ARRAY.
 * The function accepts following parameters:
 *  1. INTEGER d
 *  2. INTEGER_ARRAY arr
 */

// Solution
func rotateLeft(d int32, arr []int32) []int32 {
    arrLength := int32(len(arr))
    
    arrResult := arr[d:arrLength]
    
    for _, val := range arr[0:d]{
        arrResult = append(arrResult, int32(val))
    }
    
    return arrResult
}

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)

    firstMultipleInput := strings.Split(strings.TrimSpace(readLine(reader)), " ")

    nTemp, err := strconv.ParseInt(firstMultipleInput[0], 10, 64)
    checkError(err)
    n := int32(nTemp)

    dTemp, err := strconv.ParseInt(firstMultipleInput[1], 10, 64)
    checkError(err)
    d := int32(dTemp)

    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 := rotateLeft(d, 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)
    }
}