01: part2

1/part2.go

@@ -3,22 +3,35 @@ package main
 import (
 	"bufio"
 	"fmt"
-	"math"
 	"os"
 	"strconv"
 )
 
 func main() {
 	count := 0
-	lastValue := math.MaxInt64
+	windows := [4]int{0, 0, 0, 0}
+	i := 1
 
 	s := bufio.NewScanner(os.Stdin)
 	for s.Scan() {
+		currentWindow := i % 4
+		nextWindow := (i + 1) % 4
+
 		value, _ := strconv.Atoi(s.Text())
-		if value > lastValue {
+		for j := 0; j < 4; j++ {
+			if j != currentWindow {
+				windows[j] += value
+			}
+		}
+
+		//fmt.Println(value, windows, currentWindow, nextWindow, windows[nextWindow], windows[currentWindow])
+		// skip the first 3 values to populate the windows
+		if i > 3 && windows[nextWindow] > windows[currentWindow] {
 			count++
 		}
-		lastValue = value
+
+		windows[currentWindow] = 0
+		i++
 	}
 
 	fmt.Println(count)

1/testinput

@@ -0,0 +1,10 @@
+199
+200
+208
+210
+200
+207
+240
+269
+260
+263