feat(angch/2025-06): Initial

Author: angch

angch/2025-06/main.go

@@ -0,0 +1,148 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func day6(file string) (part1, part2 int) {
+	f, err := os.Open(file)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+
+	cells := [][]int{}
+	cells2 := [][]int{}
+
+	// ops := map[byte]bool{
+	// 	'*':true, '+':true,
+	// }
+	ops := []string{}
+	grid := [][]byte{}
+	for scanner.Scan() {
+		t := scanner.Text()
+		gridrow := []byte{}
+		for _, v := range t {
+			gridrow = append(gridrow, byte(v))
+		}
+		grid = append(grid, gridrow)
+
+		for {
+			ot := t
+			t = strings.ReplaceAll(t, "  ", " ")
+			t = strings.TrimSpace(t)
+			if t == ot {
+				break
+			}
+		}
+
+		if t[0] == '*' || t[0] == '+' {
+			ops = strings.Split(t, " ")
+			break
+		}
+
+		nums_ := strings.Split(t, " ")
+		row := []int{}
+		for _, v := range nums_ {
+			n, _ := strconv.Atoi(v)
+			row = append(row, n)
+		}
+		cells = append(cells, row)
+	}
+
+	row2 := []int{}
+	opCount := len(ops) - 1
+a:
+	for y := len(grid[0]) - 1; y >= 0; y-- {
+		s := ""
+		for x := range len(grid) - 1 {
+			if grid[x][y] != ' ' {
+				s += string(grid[x][y])
+			}
+		}
+		i, _ := strconv.Atoi(s)
+		if i == 0 {
+			if ops[opCount] == "*" {
+				out := 1
+				for _, j := range row2 {
+					out *= j
+				}
+				// fmt.Println("part2", out)
+				part2 += out
+			} else {
+				out := 0
+				for _, j := range row2 {
+					out += j
+				}
+				// fmt.Println("part2", out)
+				part2 += out
+			}
+			row2 = []int{}
+			opCount--
+			if opCount < 0 {
+				break a
+			}
+		} else {
+			row2 = append(row2, i)
+		}
+	}
+	if ops[opCount] == "*" {
+		out := 1
+		for _, j := range row2 {
+			out *= j
+		}
+		// fmt.Println("part2", out)
+		part2 += out
+	} else {
+		out := 0
+		for _, j := range row2 {
+			out += j
+		}
+		// fmt.Println("part2", out)
+		part2 += out
+	}
+	_ = cells2
+
+	// log.Printf("cells %+v\n", cells)
+	// log.Printf("%#v\n", grid)
+
+	for col, op := range ops {
+		a := 0
+		if op == "*" {
+			a = 1
+		}
+		for i := range cells {
+			// log.Println(i, col, cells[i][col])
+			if op == "*" {
+				a *= cells[i][col]
+			} else {
+				a += cells[i][col]
+			}
+		}
+		// fmt.Println(a)
+		part1 += a
+	}
+
+	return
+}
+
+func main() {
+	log.SetFlags(log.Lshortfile | log.LstdFlags)
+	t1 := time.Now()
+	part1, part2 := day6("test.txt")
+	fmt.Println(part1, part2)
+	if part1 != 4277556 || part2 != 3263827 {
+		log.Fatal("Test failed ", part1, part2)
+	}
+
+	part1, part2 = day6("input.txt")
+	fmt.Println(part1, part2)
+	fmt.Println("Elapsed time:", time.Since(t1))
+}

angch/2025-06/test.txt

@@ -0,0 +1,4 @@
+123 328  51 64 
+ 45 64  387 23 
+  6 98  215 314
+*   +   *   +