2025 advent of code day 1

day_1.R

# first star
# swap out l/r for operators
input <- apply(read.table("input.txt", header = FALSE), 1, 
               function(x) gsub("L", "-", gsub("R", "+", x)))

input <- sapply(input, function(x) eval(parse(text = x)))

start <- 50

clicks <- cumsum(c(start,input))

# sum of t/f dial point = 0
sum(clicks %% 100 == 0)

# second star
counter <- 0

# iterate over each position on dial
for (i in seq_along(input)) {
  position <- (start + input[i]) %% 100
  counter <- counter + abs(input[i]) %/% 100 # trips around the dial
  if (position == 0) {
    counter <- counter + 1
  } else if (sign(input[i]) * (position - start) < 0 & start != 0) {
    counter <- counter + 1
  }
  start <- position
}
counter