2025 Day 4 Complete!

2025/day04/main.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+func main() {
+	inp := h.StdinToStringSlice()
+	part1(inp)
+	part2(inp)
+}
+
+func part1(inp []string) {
+	var movable int
+	m := h.StringSliceToCoordByteMap(inp)
+	for c := range m.Field {
+		if m.Field[c] != '@' {
+			continue
+		}
+		if len(m.FindAdjacent(c, '@')) < 4 {
+			movable++
+		}
+	}
+	fmt.Println("# Part 1")
+	fmt.Println("Movable Rolls:",movable)
+}
+
+
+func part2(inp []string) {
+	var movable int
+	m := h.StringSliceToCoordByteMap(inp)
+	rolls := m.FindAll('@')
+	rollCnt := len(rolls)
+	prevRollCnt := 0
+	for rollCnt != prevRollCnt {
+		prevRollCnt = rollCnt
+		for i := range rolls {
+			if len(m.FindAdjacent(rolls[i], '@')) < 4 {
+				m.Put(rolls[i], '.')
+				movable++
+			}
+		}
+		rolls = m.FindAll('@')
+		rollCnt = len(rolls)
+	}
+	fmt.Println("# Part 2")
+	fmt.Println("Movable Rolls:",movable)
+}