day2

day2/day2.odin

@@ -0,0 +1,125 @@
+package main
+
+import "core:fmt"
+import "core:os"
+import "core:slice"
+import "core:strconv"
+import "core:strings"
+
+import "../utils"
+
+direction :: enum {
+	Increasing,
+	Decreasing,
+	Unknown,
+}
+
+main :: proc() {
+	input, err := utils.load_file("day2/input.txt")
+	if err != nil {
+		fmt.println("error loading input file: ", err)
+		return
+	}
+
+	reports := process_input(input)
+
+	safe_reports_count := 0
+	safe_reports_dampener_count := 0
+
+	for r in reports {
+		if is_report_safe(r) {
+			safe_reports_count += 1
+			safe_reports_dampener_count += 1
+
+			continue
+		}
+
+		if is_report_safe_dampener(r) {
+			safe_reports_dampener_count += 1
+		}
+	}
+
+	fmt.println("Safe report: ", safe_reports_count)
+	fmt.println("Safe report (problem dampener): ", safe_reports_dampener_count)
+}
+
+report_without_idx :: proc(source: []int, idx: int) -> []int {
+	output := make([]int, len(source) - 1)
+
+	j := 0
+	for i in 0 ..< len(source) {
+		if i != idx {
+			output[j] = source[i]
+			j += 1
+		}
+	}
+
+	return output
+}
+
+is_report_safe_dampener :: proc(report: []int) -> bool {
+	for i in 0 ..< len(report) {
+		if is_report_safe(report_without_idx(report, i)) {
+			return true
+		}
+	}
+
+	return false
+}
+
+
+is_report_safe :: proc(report: []int) -> bool {
+	dir := direction.Unknown
+
+	for i in 0 ..< len(report) - 1 {
+		n1 := report[i]
+		n2 := report[i + 1]
+		diff := abs(n1 - n2)
+
+		if diff < 1 || diff > 3 {
+			return false
+		}
+
+		dirdir := get_direction(n1, n2)
+
+		if dir == direction.Unknown {
+			dir = dirdir
+			continue
+		}
+
+		if dir != dirdir {
+			return false
+		}
+	}
+
+	return true
+}
+
+get_direction :: proc(n1: int, n2: int) -> direction {
+	if n1 < n2 {
+		return direction.Increasing
+	}
+
+	return direction.Decreasing
+}
+
+process_input :: proc(input: []string) -> [][]int {
+	r := make([][]int, len(input))
+
+	for line, i in input {
+		split, _ := strings.split(line, " ")
+		r[i] = convertStringToInt(split)
+	}
+
+	return r
+}
+
+convertStringToInt :: proc(str: []string) -> []int {
+	numbers := make([]int, len(str))
+
+	for i in 0 ..< len(str) {
+		numbers[i] = strconv.atoi(str[i])
+	}
+
+	return numbers
+}