Day 24 Part 2

Author: mimmackk

2024/R/day24.qmd

@@ -85,3 +85,130 @@ df |>
 
 ```
 
+## Part 2
+
+Thanks to hint from Reddit: this method of binary addition using only AND, OR, XOR gates without negation is a "ripple-carry adder."
+
+The gates follow a consistent algorithm, where "Z" digits are the final output digits, and "C" values are carried over to the next digit:
+
+```         
+
+STEP 00: 
+
+Z00 = X00 XOR Y00  (Final output: Z00)
+
+C01 = X00 AND Y00  (Carry forward to next step)
+
+STEP 01: 
+
+Z01A = X01  XOR Y01  (Intermediate step)
+Z01  = Z01A XOR C01  (Final output: Z01)
+
+C02A = X01  AND Y01  (Intermediate step)
+C02B = Z01A AND C01  (Intermediate step)
+C02  = C02A OR  C02B (Carry forward to next step)
+
+(...)
+
+C44  = C44A OR C44B  (Carry forward to next step)
+
+STEP 44:
+
+Z44A = X44  XOR Y44  (Intermediate step)
+Z44  = Z44A XOR C44  (Final output: Z45)
+
+C45A = X44  AND Y44  (Intermediate step)
+C45B = Z44A AND C44  (Intermediate step)
+C45  = C45A OR  C45B (No further steps to carry over. Set as final output: Z45)
+```
+
+We can compare the expected versus actual logic to find steps that don't match this algorithm.
+
+```{r}
+
+# Pull lists of all wires of x, y, z, and other types for quick reference
+nlist <- discard(names(wires), ~ str_starts(.x, "x|y|z"))
+xlist <- keep(names(wires), ~ str_starts(.x, "x"))
+ylist <- keep(names(wires), ~ str_starts(.x, "y"))
+zlist <- keep(names(wires), ~ str_starts(.x, "z"))
+xylist <- c(xlist, ylist)
+zmax  <- max(zlist)
+
+# Put source gates in alphabetical order for easier comparison
+gates <- gates |> 
+  mutate(src = map2(src1, src2, ~ sort(c(.x, .y)))) |> 
+  select(-c(src1, src2)) |> 
+  unnest_wider(src, names_sep = "")
+
+```
+
+Pull invalid outputs according to their gate type and inputs:
+
+```{r}
+
+invalid_by_gate <- gates |> 
+  pmap_lgl(\(gate, target, src1, src2) {
+    case_when(
+      # All z-target cases:
+      target == "z00"   ~ src1 == "x00" & src2 == "y00" & gate == "xor",
+      target == zmax    ~ src1 %in% nlist & src2 %in% nlist & gate == "|",
+      target %in% zlist ~ src1 %in% nlist & src2 %in% nlist & gate == "xor",
+      # N-target cases by gate type:
+      gate == "xor" ~ src1 %in% xylist & src2 %in% xylist,
+      gate == "|"   ~ src1 %in% nlist  & src2 %in% nlist
+    )
+  }) |> 
+  set_names(gates$target) |> 
+  keep(~ !is.na(.x) & .x == FALSE) |> 
+  names()
+
+```
+
+Identify invalid outputs by following their logic trail forward and checking the gate types of the logic they are used as later input for:
+
+```{r}
+
+invalid_by_path <- gates |> 
+  left_join(select(gates, src1, gate), join_by(x$target == y$src1), suffix = c("", "1")) |> 
+  left_join(select(gates, src2, gate), join_by(x$target == y$src2), suffix = c("", "2")) |> 
+  nest(nxt = c(gate1, gate2), .by = -c(gate1, gate2)) |> 
+  mutate(
+    nxt = map(nxt, ~ .x |> unlist() |> discard(is.na) |> unname())
+  ) |> 
+  unnest_wider(nxt, names_sep = "_") |> 
+  mutate(
+    valid = case_when(
+      target %in% zlist 
+        ~ NA,
+      gate == "xor" 
+        ~ nxt_1 %in% c("xor", "&") & 
+          nxt_2 %in% c("xor", "&") & 
+          nxt_1 != nxt_2 & 
+          !is.na(nxt_1) & 
+          !is.na(nxt_2),
+      gate == "|" 
+        ~ nxt_1 %in% c("xor", "&") & 
+          nxt_2 %in% c("xor", "&") & 
+          nxt_1 != nxt_2 & 
+          !is.na(nxt_1) & 
+          !is.na(nxt_2),
+      gate == "&" & !(src1 %in% c("x00", "y00"))
+        ~ nxt_1 == "|" | nxt_2 == "|"
+    )
+  ) |> 
+  filter(!valid) |> 
+  pull(target)
+
+
+```
+
+Concatenate all invalid gates alphabetically:
+
+```{r}
+
+c(invalid_by_gate, invalid_by_path) |> 
+  unique() |> 
+  sort() |> 
+  str_c(collapse = ",")
+
+```

_freeze/2024/R/day24/execute-results/html.json

@@ -1,8 +1,8 @@
 {
-  "hash": "ff6b3b2e4bd09923c3cd47bfefe5126a",
+  "hash": "d39d73305f3974562115d8a17d9e6f3d",
   "result": {
     "engine": "knitr",
-    "markdown": "---\ntitle: \"Day 24\"\ndate: 2024-12-24\nauthor:\n  name: https://adventofcode.com/2024/day/24\n  url: https://adventofcode.com/2024/day/24\n---\n\n\n\n\n## Setup\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\n# Libraries\nlibrary(tidyverse)\n\n# Read input from file\ninput <- read_lines(\"../input/day24.txt\", skip_empty_rows = TRUE)\n```\n:::\n\n\n\n\n## Part 1\n\nConvert input to lists of gates and wires:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ninit <- input |> \n  unglue::unglue_data(\"{wire}: {value}\", convert = TRUE) |> \n  filter(!is.na(wire))\n\ngates <- input |> \n  unglue::unglue_data(\"{src1} {gate} {src2} -> {target}\") |> \n  filter(!is.na(gate)) |> \n  mutate(gate = case_match(gate, \"AND\" ~ \"&\", \"OR\" ~ \"|\", \"XOR\" ~ \"xor\"))\n\nwires <- init |> \n  complete(wire = unique(c(gates$src1, gates$src2, gates$target))) |> \n  deframe()\n```\n:::\n\n\n\n\nLoop through the lists of gates and wires, and whenever a new gate can be activated, get its resulting value. Repeat until all wires have a final output.\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ndf <- wires |> \n  enframe(name = \"wire\") |>\n  left_join(gates, join_by(wire == target))\n\nrepeat {\n\n  cur_values <- df |> \n    select(wire, value) |> \n    deframe()\n  \n  df <- df |> \n    mutate(\n      val1 = cur_values[src1], \n      val2 = cur_values[src2],\n      value = coalesce(\n        value,\n        pmap_int(list(gate, val1, val2), \\(gate, val1, val2) {\n          if (!is.na(gate) & !is.na(val1) & !is.na(val2))\n            get(gate)(val1, val2)\n          else \n            NA_integer_\n        })\n      )\n    )\n  \n  if (all(!is.na(df$value))) break\n}\n```\n:::\n\n\n\n\nConvert the Z-coded wires to a binary number:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ndf |> \n  filter(str_starts(wire, \"z\")) |> \n  arrange(wire) |> \n  pull(value) |> \n  imap_dbl(\\(x, i) x * 2^(i - 1)) |> \n  sum() |> \n  format(scientific = FALSE)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] \"59364044286798\"\n```\n\n\n:::\n:::\n",
+    "markdown": "---\ntitle: \"Day 24\"\ndate: 2024-12-24\nauthor:\n  name: https://adventofcode.com/2024/day/24\n  url: https://adventofcode.com/2024/day/24\n---\n\n\n\n\n## Setup\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\n# Libraries\nlibrary(tidyverse)\n\n# Read input from file\ninput <- read_lines(\"../input/day24.txt\", skip_empty_rows = TRUE)\n```\n:::\n\n\n\n\n## Part 1\n\nConvert input to lists of gates and wires:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ninit <- input |> \n  unglue::unglue_data(\"{wire}: {value}\", convert = TRUE) |> \n  filter(!is.na(wire))\n\ngates <- input |> \n  unglue::unglue_data(\"{src1} {gate} {src2} -> {target}\") |> \n  filter(!is.na(gate)) |> \n  mutate(gate = case_match(gate, \"AND\" ~ \"&\", \"OR\" ~ \"|\", \"XOR\" ~ \"xor\"))\n\nwires <- init |> \n  complete(wire = unique(c(gates$src1, gates$src2, gates$target))) |> \n  deframe()\n```\n:::\n\n\n\n\nLoop through the lists of gates and wires, and whenever a new gate can be activated, get its resulting value. Repeat until all wires have a final output.\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ndf <- wires |> \n  enframe(name = \"wire\") |>\n  left_join(gates, join_by(wire == target))\n\nrepeat {\n\n  cur_values <- df |> \n    select(wire, value) |> \n    deframe()\n  \n  df <- df |> \n    mutate(\n      val1 = cur_values[src1], \n      val2 = cur_values[src2],\n      value = coalesce(\n        value,\n        pmap_int(list(gate, val1, val2), \\(gate, val1, val2) {\n          if (!is.na(gate) & !is.na(val1) & !is.na(val2))\n            get(gate)(val1, val2)\n          else \n            NA_integer_\n        })\n      )\n    )\n  \n  if (all(!is.na(df$value))) break\n}\n```\n:::\n\n\n\n\nConvert the Z-coded wires to a binary number:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ndf |> \n  filter(str_starts(wire, \"z\")) |> \n  arrange(wire) |> \n  pull(value) |> \n  imap_dbl(\\(x, i) x * 2^(i - 1)) |> \n  sum() |> \n  format(scientific = FALSE)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] \"59364044286798\"\n```\n\n\n:::\n:::\n\n\n\n\n## Part 2\n\nThanks to hint from Reddit: this method of binary addition using only AND, OR, XOR gates without negation is a \"ripple-carry adder.\"\n\nThe gates follow a consistent algorithm, where \"Z\" digits are the final output digits, and \"C\" values are carried over to the next digit:\n\n```         \n\nSTEP 00: \n\nZ00 = X00 XOR Y00  (Final output: Z00)\n\nC01 = X00 AND Y00  (Carry forward to next step)\n\nSTEP 01: \n\nZ01A = X01  XOR Y01  (Intermediate step)\nZ01  = Z01A XOR C01  (Final output: Z01)\n\nC02A = X01  AND Y01  (Intermediate step)\nC02B = Z01A AND C01  (Intermediate step)\nC02  = C02A OR  C02B (Carry forward to next step)\n\n(...)\n\nC44  = C44A OR C44B  (Carry forward to next step)\n\nSTEP 44:\n\nZ44A = X44  XOR Y44  (Intermediate step)\nZ44  = Z44A XOR C44  (Final output: Z45)\n\nC45A = X44  AND Y44  (Intermediate step)\nC45B = Z44A AND C44  (Intermediate step)\nC45  = C45A OR  C45B (No further steps to carry over. Set as final output: Z45)\n```\n\nWe can compare the expected versus actual logic to find steps that don't match this algorithm.\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\n# Pull lists of all wires of x, y, z, and other types for quick reference\nnlist <- discard(names(wires), ~ str_starts(.x, \"x|y|z\"))\nxlist <- keep(names(wires), ~ str_starts(.x, \"x\"))\nylist <- keep(names(wires), ~ str_starts(.x, \"y\"))\nzlist <- keep(names(wires), ~ str_starts(.x, \"z\"))\nxylist <- c(xlist, ylist)\nzmax  <- max(zlist)\n\n# Put source gates in alphabetical order for easier comparison\ngates <- gates |> \n  mutate(src = map2(src1, src2, ~ sort(c(.x, .y)))) |> \n  select(-c(src1, src2)) |> \n  unnest_wider(src, names_sep = \"\")\n```\n:::\n\n\n\n\nPull invalid outputs according to their gate type and inputs:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ninvalid_by_gate <- gates |> \n  pmap_lgl(\\(gate, target, src1, src2) {\n    case_when(\n      # All z-target cases:\n      target == \"z00\"   ~ src1 == \"x00\" & src2 == \"y00\" & gate == \"xor\",\n      target == zmax    ~ src1 %in% nlist & src2 %in% nlist & gate == \"|\",\n      target %in% zlist ~ src1 %in% nlist & src2 %in% nlist & gate == \"xor\",\n      # N-target cases by gate type:\n      gate == \"xor\" ~ src1 %in% xylist & src2 %in% xylist,\n      gate == \"|\"   ~ src1 %in% nlist  & src2 %in% nlist\n    )\n  }) |> \n  set_names(gates$target) |> \n  keep(~ !is.na(.x) & .x == FALSE) |> \n  names()\n```\n:::\n\n\n\n\nIdentify invalid outputs by following their logic trail forward and checking the gate types of the logic they are used as later input for:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\ninvalid_by_path <- gates |> \n  left_join(select(gates, src1, gate), join_by(x$target == y$src1), suffix = c(\"\", \"1\")) |> \n  left_join(select(gates, src2, gate), join_by(x$target == y$src2), suffix = c(\"\", \"2\")) |> \n  nest(nxt = c(gate1, gate2), .by = -c(gate1, gate2)) |> \n  mutate(\n    nxt = map(nxt, ~ .x |> unlist() |> discard(is.na) |> unname())\n  ) |> \n  unnest_wider(nxt, names_sep = \"_\") |> \n  mutate(\n    valid = case_when(\n      target %in% zlist \n        ~ NA,\n      gate == \"xor\" \n        ~ nxt_1 %in% c(\"xor\", \"&\") & \n          nxt_2 %in% c(\"xor\", \"&\") & \n          nxt_1 != nxt_2 & \n          !is.na(nxt_1) & \n          !is.na(nxt_2),\n      gate == \"|\" \n        ~ nxt_1 %in% c(\"xor\", \"&\") & \n          nxt_2 %in% c(\"xor\", \"&\") & \n          nxt_1 != nxt_2 & \n          !is.na(nxt_1) & \n          !is.na(nxt_2),\n      gate == \"&\" & !(src1 %in% c(\"x00\", \"y00\"))\n        ~ nxt_1 == \"|\" | nxt_2 == \"|\"\n    )\n  ) |> \n  filter(!valid) |> \n  pull(target)\n```\n:::\n\n\n\n\nConcatenate all invalid gates alphabetically:\n\n\n\n\n::: {.cell}\n\n```{.r .cell-code}\nc(invalid_by_gate, invalid_by_path) |> \n  unique() |> \n  sort() |> \n  str_c(collapse = \",\")\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] \"cbj,cfk,dmn,gmt,qjj,z07,z18,z35\"\n```\n\n\n:::\n:::\n",
     "supporting": [],
     "filters": [
       "rmarkdown/pagebreak.lua"

docs/2022/R/day01.html

@@ -67,7 +67,7 @@
 <script src="../../site_libs/quarto-search/quarto-search.js"></script>
 <meta name="quarto:offset" content="../../">
 <link href="../../2022/R/day02.html" rel="next">
-<link href="../../2024/R/day23.html" rel="prev">
+<link href="../../2024/R/day24.html" rel="prev">
 <script src="../../site_libs/quarto-html/quarto.js"></script>
 <script src="../../site_libs/quarto-html/popper.min.js"></script>
 <script src="../../site_libs/quarto-html/tippy.umd.min.js"></script>
@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 1</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 1</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -907,8 +919,8 @@ <h2 class="anchored" data-anchor-id="part-2">Part 2</h2>
 </script>
 <nav class="page-navigation">
   <div class="nav-page nav-page-previous">
-      <a href="../../2024/R/day23.html" class="pagination-link" aria-label="Day 23">
-        <i class="bi bi-arrow-left-short"></i> <span class="nav-page-text">Day 23</span>
+      <a href="../../2024/R/day24.html" class="pagination-link" aria-label="Day 24">
+        <i class="bi bi-arrow-left-short"></i> <span class="nav-page-text">Day 24</span>
       </a>          
   </div>
   <div class="nav-page nav-page-next">

docs/2022/R/day02.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 2</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 2</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>

docs/2022/R/day03.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 3</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 3</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
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docs/2022/R/day04.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 4</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 4</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>

docs/2022/R/day05.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 5</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 5</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>

docs/2022/R/day06.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 6</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 6</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>

docs/2022/R/day07.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 7</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 7</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>

docs/2022/R/day08.html

@@ -281,6 +281,12 @@ <h1 class="quarto-secondary-nav-title">Day 8</h1>
   <a href="../../2024/R/day23.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 23</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2024/R/day24.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 24</span></a>
+  </div>
 </li>
       </ul>
   </li>
@@ -382,6 +388,12 @@ <h1 class="quarto-secondary-nav-title">Day 8</h1>
   <a href="../../2022/R/day15.html" class="sidebar-item-text sidebar-link">
  <span class="menu-text">Day 15</span></a>
   </div>
+</li>
+          <li class="sidebar-item">
+  <div class="sidebar-item-container"> 
+  <a href="../../2022/R/day16.html" class="sidebar-item-text sidebar-link">
+ <span class="menu-text">Day 16</span></a>
+  </div>
 </li>
       </ul>
   </li>