2025 Day 2 Complete!

2025/day02/main.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+func main() {
+	inp := h.StdinToString()
+	part1(inp)
+	part2(inp)
+}
+
+func part1(inp string) {
+	var res int
+	ranges := getRanges(inp)
+	for _, rng := range ranges {
+		for wrk := rng.beg; wrk <= rng.end; wrk++ {
+			sWrk := h.Itoa(wrk)
+			hlf := len(sWrk) / 2
+			if sWrk[:hlf] == sWrk[hlf:] {
+				res += wrk
+			}
+		}
+	}
+	fmt.Println("# Part 1")
+	fmt.Println(res)
+}
+
+func part2(inp string) {
+	var res int
+	ranges := getRanges(inp)
+	for _, rng := range ranges {
+		for wrk := rng.beg; wrk <= rng.end; wrk++ {
+			sWrk := h.Itoa(wrk)
+			cnt := len(sWrk)
+			for i := 0; i < cnt/2; i++ {
+				ch := i + 1
+				if cnt%ch != 0 { // Must be divisible
+					continue
+				}
+				if strings.Repeat(sWrk[:ch], cnt/ch) == sWrk {
+					res += wrk
+					break
+				}
+			}
+		}
+	}
+	fmt.Println("# Part 2")
+	fmt.Println(res)
+}
+
+type Range struct {
+	beg, end int
+}
+
+func getRanges(inp string) []Range {
+	ret := []Range{}
+	segs := strings.Split(inp, ",")
+	for i := range segs {
+		pts := strings.Split(segs[i], "-")
+		ret = append(ret, Range{beg: h.Atoi(pts[0]), end: h.Atoi(pts[1])})
+	}
+	return ret
+}