day06.Rmd

---
title: "--- Day 6: Custom Customs ---"
author: Fleur Kelpin
date: Dec 6, 2020
output: github_document
---

```{r message=FALSE, warning=FALSE}
library(tidyverse)
input <- readr::read_file("day06.txt") %>%
  str_split("\n\n") %>%
  unlist()
tibble(input)
```

# Part 1

For each group, count the number of questions to which anyone answered "yes".
What is the sum of those counts?

```{r}
input %>%
  str_match_all("\\w") %>%
  map_dbl(
    ~ unique(.) %>%
      length()
  ) %>%
  sum()
```
# Part 2

For each group, count the number of questions to which everyone answered "yes".
What is the sum of those counts?

```{r}
input %>%
  str_split("\n") %>%
  map_dbl(
    ~ str_split(., "") %>%
      reduce(intersect) %>%
      length()
  ) %>%
  sum()
```