commit e32ec9ee60192eb5a49b48830318adfaedf58cd3
parent 3aa4adb519229ec0d4751a15e3e77467a55d4324
Author: Eamon Caddigan <ec@eamoncaddigan.net>
Date: Sat, 6 Dec 2025 20:53:12 -0800
Solve day 06, part 1
Diffstat:
| A | src/day06.R | | | 48 | ++++++++++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 48 insertions(+), 0 deletions(-)
diff --git a/src/day06.R b/src/day06.R
@@ -0,0 +1,48 @@
+#!/usr/bin/env Rscript
+
+source("src/utils.R")
+
+test_input <- c(
+ "123 328 51 64 ",
+ " 45 64 387 23 ",
+ " 6 98 215 314",
+ "* + * + "
+)
+puzzle_input <- aoc_input(6)
+
+parse_input <- function(input_lines) {
+ split_lines <- strsplit(trimws(input_lines), "\\s+")
+ list(
+ numbers = split_lines[1:(length(split_lines) - 1)] |>
+ unlist() |>
+ as.numeric() |>
+ matrix(nrow = length(split_lines) - 1, byrow = TRUE),
+ operators = split_lines[[length(split_lines)]]
+ )
+}
+
+solve_problems <- function(numbers, operators) {
+ sum(c(
+ apply(numbers[, operators == "+"], 2, sum),
+ apply(numbers[, operators == "*"], 2, prod)
+ ))
+}
+
+part1 <- function(input_lines) {
+ input_parsed <- parse_input(input_lines)
+ solve_problems(
+ input_parsed$numbers,
+ input_parsed$operators
+ )
+}
+
+test_part1 <- function() {
+ stopifnot(part1(test_input) == 4277556)
+}
+
+main <- function() {
+ test_part1()
+ cat(sprintf("Part 1 solution: %0.0f\n", part1(puzzle_input)))
+}
+
+main()
