add: maps project — log parser

23-project-log-parser/02-project-file-parser/log.txt

@@ -0,0 +1,11 @@
+learngoprogramming.com 10
+learngoprogramming.com 5
+learngoprogramming.com 
+learngoprogramming.com 20
+golang.org 4
+golang.org 6
+golang.org 5
+golang.org 10
+blog.golang.org 5
+blog.golang.org 20
+blog.golang.org 10

23-project-log-parser/02-project-file-parser/main.go

@@ -0,0 +1,65 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	var (
+		// Stores the visits per unique domain
+		sum = make(map[string]int)
+
+		// Stores the unique domain names for printing
+		domains []string
+
+		in = bufio.NewScanner(os.Stdin)
+	)
+
+	// Scan the standard-in line by line
+	for line := 0; in.Scan(); line++ {
+
+		// Parse the fields
+		fields := strings.Fields(in.Text())
+		if len(fields) != 2 {
+			fmt.Printf("wrong input: %v (line #%d)\n", fields, line)
+			return
+		}
+		domain, visits := fields[0], fields[1]
+
+		// Collect the unique domains
+		if _, ok := sum[domain]; !ok {
+			domains = append(domains, domain)
+		}
+
+		// Sum the total visits per domain
+		n, _ := strconv.Atoi(visits)
+		if n < 0 {
+			fmt.Printf("wrong input: %q (line #%d)\n", visits, line)
+			return
+		}
+		sum[domain] += n
+	}
+
+	// Print the visits per domain
+	var total int
+	for _, domain := range domains {
+		hits := sum[domain]
+
+		fmt.Printf("%-25s -> %d\n", domain, hits)
+		total += hits
+	}
+
+	// Print the total visits for all domains
+	fmt.Printf("\n%-25s -> %d\n", "TOTAL", total)
+}