Use math.MinInt and fmt.Sscanf

Author: mjlshen

day01/main.go

@@ -3,8 +3,8 @@ package main
 import (
 "bufio"
 "fmt"
+"math"
 "os"
-"strconv"
 )
 
 func main() {
@@ -20,12 +20,12 @@ func numIncreases(path string) int {
 }
 defer file.Close()
 
-prev, ans := 0, -1
+prev, ans := math.MinInt, -1
 
 scanner := bufio.NewScanner(file)
 for scanner.Scan() {
-m, err := strconv.Atoi(scanner.Text())
-if err != nil {
+var m int
+if _, err := fmt.Sscanf(scanner.Text(), "%d", &m); err != nil {
 panic(err)
 }
 if m > prev {
@@ -45,24 +45,20 @@ func numIncreasesWindow(path string, w int) int {
 }
 defer file.Close()
 
-prev, ans := 0, -1
+prev, ans := math.MinInt, -1
 window := make([]int, w)
-i := 0
 
 scanner := bufio.NewScanner(file)
-for scanner.Scan() {
+for i := 0; scanner.Scan(); i++ {
 if i < w-1 {
-window[i], err = strconv.Atoi(scanner.Text())
-if err != nil {
+if _, err := fmt.Sscanf(scanner.Text(), "%d", &window[i]); err != nil {
 panic(err)
 }
-i++
 continue
-} else {
-window[len(window)-1], err = strconv.Atoi(scanner.Text())
-if err != nil {
-panic(err)
-}
+}
+
+if _, err := fmt.Sscanf(scanner.Text(), "%d", &window[len(window)-1]); err != nil {
+panic(err)
 }
 
 m := sum(window)
@@ -91,6 +87,4 @@ func shift(a []int) []int {
 a[i-1] = a[i]
 }
 return a
-
-// return append(a[1:], 0) This also works but allocates a new slice?
 }