Added Day 4

day4/d4p2.go

@@ -0,0 +1,71 @@
+// +build linux
+package main
+
+import (
+    "fmt"
+    //"io"
+    //"bufio"
+    "os"
+    "strings"
+    "regexp"
+)
+
+func find_num_wins(winners string, numbers string) int {
+    wins := 0
+    for _, number := range strings.Split(numbers, " ") {
+        for _, winner := range strings.Split(winners, " ") {
+            if number == winner && len(number) > 0 {
+                wins++
+            }
+        }
+    }
+    return wins
+}
+
+
+func main() {
+    if len(os.Args) < 2 {
+        panic("You did not specify an input file.")
+    }
+
+    rawInput, err := os.ReadFile(os.Args[1])
+    if err != nil {
+        panic(err)
+    }
+
+    stringInput := strings.Trim(string(rawInput), "\n")
+    stringInput = regexp.MustCompile(`(Card.*:\ )`).ReplaceAllString(stringInput, "")
+
+    lines := strings.Split(stringInput, "\n")
+
+    var cards []int
+    cards = make([]int, len(lines))
+
+    for i,_ := range cards {
+        cards[i] = 1
+    }
+
+    sum := 0
+
+    for card, game := range lines {
+        if len(game) < 10 {
+            continue
+        }
+
+        game_ := strings.Split(game, " | ")
+        winners := game_[0]
+        numbers := game_[1]
+
+        wins := find_num_wins(numbers, winners)
+
+        sum += cards[card]
+
+        for i := 0; i < wins; i++ {
+            cards[card+i+1] += cards[card]
+        }
+
+        fmt.Println(card+1, cards[card])
+    }
+
+    fmt.Println("Answer: ", sum)
+}

day4/sample1

@@ -0,0 +1,6 @@
+Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11