solve day4 part1

2024/day4/day4.go

@@ -0,0 +1,62 @@
+package day4
+
+import (
+	"adventofcode/utils"
+	"strings"
+)
+
+func Part1(file string) int {
+	lines := utils.ReadFileByLine(file)
+
+	result := 0
+	for i, line := range lines {
+		for j, _ := range line {
+			letters := strings.Split(line, "")
+			if letters[j] == "X" || letters[j] == "S" {
+				// right
+				if len(letters)-3 > j {
+					straight := strings.Join(letters[j:j+4], "")
+					if Holliday(straight) {
+						result += 1
+					}
+				}
+
+				// down
+				if len(lines)-3 > i {
+					down := strings.Join([]string{string(lines[i][j]), string(lines[i+1][j]), string(lines[i+2][j]), string(lines[i+3][j])}, "")
+					if Holliday(down) {
+						// fmt.Println(down)
+						result += 1
+					}
+				}
+
+				// diagonal down right
+				if len(lines)-3 > i && len(letters)-3 > j {
+					ddr := strings.Join([]string{string(lines[i][j]), string(lines[i+1][j+1]), string(lines[i+2][j+2]), string(lines[i+3][j+3])}, "")
+					if Holliday(ddr) {
+						result += 1
+					}
+				}
+				// diagonal down left
+				if len(lines)-3 > i && 3 <= j {
+					ddl := strings.Join([]string{string(lines[i][j]), string(lines[i+1][j-1]), string(lines[i+2][j-2]), string(lines[i+3][j-3])}, "")
+					if Holliday(ddl) {
+						result += 1
+					}
+				}
+			}
+		}
+	}
+	return result
+}
+
+func Part2(file string) int {
+	// lines := utils.ReadFileByLine(file)
+	result := 0
+
+	return result
+}
+
+func Holliday(holliday string) bool {
+	return (holliday == "XMAS" || holliday == "SAMX")
+}