adds timing to each days file

Author: tomjemmett

day_01.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 1](https://adventofcode.com/2020/day/1).
@@ -247,3 +249,7 @@ def part_2_py(input_values, target):
 bench::mark(part_2_improved(actual, 2020),
             py$part_2_py(actual, 2020))
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_02.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 2](https://adventofcode.com/2020/day/2).
@@ -126,3 +128,7 @@ This matches the example, so we can now solve part 2.
 ```{r part 2 solution}
 length(part_2_valid_passwords(actual))
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_03.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 3](https://adventofcode.com/2020/day/3).
@@ -149,3 +151,7 @@ The other combinations would be going just 1 down at each step, and then all of
 that the greatest common divisor of right and down is 1. This would give us all of the movements that don't violate the
 constraint above of a non-unique movement. For instance, 6 right, 2 down has a greatest common divisor of 2, and this
 combination is the same as 3 right, 1 down.
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_04.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 4](https://adventofcode.com/2020/day/4).
@@ -191,3 +193,7 @@ actual %>%
   map_lgl(compose(all, flatten_lgl)) %>%
   sum()
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_05.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 5](https://adventofcode.com/2020/day/5).
@@ -110,3 +112,7 @@ triangle_number <- function(n) 0.5 * n * (n + 1)
 
 triangle_number(max(seats)) - triangle_number(min(seats) - 1) - sum(seats)
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_06.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 6](https://adventofcode.com/2020/day/6).
@@ -112,3 +114,7 @@ We can now check that this new function works as expected:
 extra(actual, union) == part_1(actual)
 extra(actual, intersect) == part_2(actual)
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_07.Rmd

@@ -7,6 +7,8 @@ library(tidyverse)
 library(igraph)
 library(ggraph)
 library(unglue)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 7](https://adventofcode.com/2020/day/7).
@@ -154,3 +156,7 @@ part_2_alt(sample_g, "shiny gold", 1) - 1 == part_2(sample_g)
 ```{r extra part 2 alt actual test}
 part_2_alt(actual_g, "shiny gold", 1) - 1 == part_2(actual_g)
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_08.Rmd

@@ -6,6 +6,8 @@ options(crayon.enabled = NULL)
 library(tidyverse)
 library(R6)
 library(unglue)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 8](https://adventofcode.com/2020/day/8).
@@ -321,3 +323,7 @@ Computer <- R6Class(
   )
 )
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_09.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 9](https://adventofcode.com/2020/day/9).
@@ -89,3 +91,7 @@ And run on the actual input:
 ```{r part 2 sample actual}
 part_2(actual, pa1)
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*

day_10.Rmd

@@ -4,6 +4,8 @@
 knitr::opts_chunk$set(echo = TRUE)
 options(crayon.enabled = NULL)
 library(tidyverse)
+
+START_TIME <- Sys.time()
 ```
 
 This is my attempt to solve [Day 10](https://adventofcode.com/2020/day/10).
@@ -86,3 +88,7 @@ notation by setting the `scipen` option.
 options(scipen = 999)
 part_2(actual)
 ```
+
+---
+
+*Elapsed Time: `r round(Sys.time() - START_TIME, 3)`s*