# Advent of Code: Day 6

## Parts 1 and 2

The result of part 1 and 2 are returned by the list.

I wasted quite a bit of time on this puzzle, as I was implementing the redistribution incorrectly at first. Once again this is not very elegant, I’m sure there are ways to improve the computing speed and clarity of the code.xs

```
puzzle_input <- c("4 10 4 1 8 4 9 14 5 1 14 15 0 15 3 5")
puzzle_input <- as.numeric(unlist(strsplit(puzzle_input, "\\t")))
## x: value to distribute
## n: number of elements to distribute it over
allocate <- function(x, n) {
res <- integer(n)
pos <- 1
i <- 1
while (i <= x && sum(res) < x) {
res[pos] <- res[pos] + 1
pos <- pos + 1
if (pos == n + 1) pos <- 1
i <- i + 1
}
res
}
count_cycles <- function(input) {
step <- 0
visited <- character(0)
while (!paste(input, collapse = " ") %in% visited) {
visited <- c(visited, paste(input, collapse = " "))
max_i <- which.max(input)
to_distribute <- allocate(input[max_i], length(input))
## reorder the distribution
offset <- length(input) - max_i
if (offset != 0) {
to_distribute <- c(tail(to_distribute, -offset),
head(to_distribute, offset))
}
input[max_i] <- 0
input <- input + to_distribute
step <- step + 1
}
list(
steps = step,
loop_size = (step - which(paste(input, collapse = " ") == visited)) + 1
)
}
count_cycles(c(0, 2, 7, 0))
```

```
## $steps
## [1] 5
##
## $loop_size
## [1] 4
```

```
count_cycles(puzzle_input)
```

```
## $steps
## [1] 12841
##
## $loop_size
## [1] 8038
```

## Comments