Solve 2019 Day 2

Signed-off-by: Alexander Kurbatov <sir.alkurbatov@yandex.ru>

Author: alkurbatov

2019/2/main.go

@@ -0,0 +1,98 @@
+// --- Day 2: 1202 Program Alarm ---
+// https://adventofcode.com/2019/day/2
+package main
+
+import (
+	"bufio"
+	"log"
+	"os"
+
+	"github.com/alkurbatov/adventofcode/internal/parsers"
+)
+
+func readInput(path string) ([]int, error) {
+	input, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer input.Close()
+
+	scanner := bufio.NewScanner(input)
+	scanner.Scan()
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return parsers.ReadNumbers(scanner.Text(), ",")
+}
+
+func runIntcode(program []int) int {
+	i := 0
+
+	for i < len(program) {
+		instruction := program[i]
+
+		if instruction == 99 {
+			break
+		}
+
+		p1 := program[i+1]
+		p2 := program[i+2]
+		p3 := program[i+3]
+
+		switch instruction {
+		case 1:
+			program[p3] = program[p1] + program[p2]
+		case 2:
+			program[p3] = program[p1] * program[p2]
+		}
+
+		i += 4
+	}
+
+	return program[0]
+}
+
+func restoreGravityAssist(program []int) int {
+	programCopy := append([]int(nil), program...)
+
+	// Apply rules
+	programCopy[1] = 12 // noun
+	programCopy[2] = 2  // verb
+
+	return runIntcode(programCopy)
+}
+
+func completeGravityAssist(program []int) (noun, verb int) {
+	for noun = 0; noun < 100; noun++ {
+		for verb = 0; verb < 100; verb++ {
+			programCopy := append([]int(nil), program...)
+
+			// Apply rules
+			programCopy[1] = noun
+			programCopy[2] = verb
+
+			if runIntcode(programCopy) == 19690720 {
+				return noun, verb
+			}
+		}
+	}
+
+	return noun, verb
+}
+
+func main() {
+	program, err := readInput("./2019/2/input.txt")
+	if err != nil {
+		log.Printf("Failed to read data from input.txt: %v", err)
+		return
+	}
+
+	firstPartResult := restoreGravityAssist(program)
+	log.Printf("Part 1 result: %d", firstPartResult)
+
+	noun, verb := completeGravityAssist(program)
+	secondPartResult := 100*noun + verb
+	log.Printf("Part 2 result: %d", secondPartResult)
+}

2023/9/main.go

@@ -21,7 +21,7 @@ func readInput(path string) ([][]int, error) {
 	result := make([][]int, 0)
 
 	for scanner.Scan() {
-		sequence, err := parsers.ReadNumbers(scanner.Text())
+		sequence, err := parsers.ReadNumbers(scanner.Text(), " ")
 		if err != nil {
 			return nil, err
 		}

internal/parsers/numbers.go

@@ -6,10 +6,10 @@ import (
 )
 
 // Read sequence of numbers from string.
-func ReadNumbers(src string) ([]int, error) {
+func ReadNumbers(src, sep string) ([]int, error) {
 	result := make([]int, 0)
 
-	for _, field := range strings.Fields(src) {
+	for _, field := range strings.Split(src, sep) {
 		num, err := strconv.Atoi(field)
 		if err != nil {
 			return nil, err