Solve p8 in lua

README.rst

@@ -93,7 +93,7 @@ Olivia's Project Euler Solutions
    |            | Browser [#]_               |        | |CodeQL| |br|     |
    |            |                            |        | |ESLint|          |
    +------------+----------------------------+--------+-------------------+
-   | Lua        | Lua 5+ [#]_                | 10     | |Luai| |br|       |
+   | Lua        | Lua 5+ [#]_                | 11     | |Luai| |br|       |
    |            |                            |        | |LuaCheck|        |
    +------------+----------------------------+--------+-------------------+
    | Python     | CPython 3.6+ |br|          | 80     | |Python| |br|     |

docs/index.rst

@@ -91,7 +91,7 @@ Problems Solved
   +-----------+-----------+------------+------------+------------+------------+------------+------------+------------+
   |:prob:`007`|:c-d:`0007`|:cp-d:`0007`|:cs-d:`0007`|            |:js-d:`0007`|            |:py-d:`0007`|:rs-d:`0007`|
   +-----------+-----------+------------+------------+------------+------------+------------+------------+------------+
-  |:prob:`008`|:c-d:`0008`|:cp-d:`0008`|:cs-d:`0008`|:ja-d:`0008`|:js-d:`0008`|            |:py-d:`0008`|:rs-d:`0008`|
+  |:prob:`008`|:c-d:`0008`|:cp-d:`0008`|:cs-d:`0008`|:ja-d:`0008`|:js-d:`0008`|:lu-d:`0008`|:py-d:`0008`|:rs-d:`0008`|
   +-----------+-----------+------------+------------+------------+------------+------------+------------+------------+
   |:prob:`009`|:c-d:`0009`|:cp-d:`0009`|:cs-d:`0009`|:ja-d:`0009`|:js-d:`0009`|:lu-d:`0009`|:py-d:`0009`|:rs-d:`0009`|
   +-----------+-----------+------------+------------+------------+------------+------------+------------+------------+

docs/src/lua/p0008.rst

@@ -0,0 +1,16 @@
+Lua Implementation of Problem 8
+===============================
+
+View source code :source:`lua/src/p0008.lua`
+
+Solution
+--------
+
+.. lua:function:: solution()
+
+    :return: The solution to problem 8
+    :rtype: number
+
+.. literalinclude:: ../../../lua/src/p0008.lua
+   :language: Lua
+   :linenos:

lua/README.rst

@@ -59,6 +59,7 @@ Problems Solved
 -  ☒ `2 <./src/p0002.lua>`__
 -  ☒ `4 <./src/p0004.lua>`__
 -  ☒ `6 <./src/p0006.lua>`__
+-  ☒ `8 <./src/p0008.lua>`__
 -  ☒ `9 <./src/p0009.lua>`__
 -  ☒ `17 <./src/p0017.lua>`__
 -  ☒ `28 <./src/p0028.lua>`__

lua/src/p0008.lua

@@ -0,0 +1,73 @@
+-- Project Euler Problem 8
+--
+-- Problem:
+--
+-- The four adjacent digits in the 1000-digit number that have the greatest
+-- product are 9 × 9 × 8 × 9 = 5832.
+--
+-- 73167176531330624919225119674426574742355349194934
+-- 96983520312774506326239578318016984801869478851843
+-- 85861560789112949495459501737958331952853208805511
+-- 12540698747158523863050715693290963295227443043557
+-- 66896648950445244523161731856403098711121722383113
+-- 62229893423380308135336276614282806444486645238749
+-- 30358907296290491560440772390713810515859307960866
+-- 70172427121883998797908792274921901699720888093776
+-- 65727333001053367881220235421809751254540594752243
+-- 52584907711670556013604839586446706324415722155397
+-- 53697817977846174064955149290862569321978468622482
+-- 83972241375657056057490261407972968652414535100474
+-- 82166370484403199890008895243450658541227588666881
+-- 16427171479924442928230863465674813919123162824586
+-- 17866458359124566529476545682848912883142607690042
+-- 24219022671055626321111109370544217506941658960408
+-- 07198403850962455444362981230987879927244284909188
+-- 84580156166097919133875499200524063689912560717606
+-- 05886116467109405077541002256983155200055935729725
+-- 71636269561882670428252483600823257530420752963450
+--
+-- Find the thirteen adjacent digits in the 1000-digit number that have the
+-- greatest product. What is the value of this product?
+
+return {
+    solution = function()
+        string = ("73167176531330624919225119674426574742355349194934"
+               .. "96983520312774506326239578318016984801869478851843"
+               .. "85861560789112949495459501737958331952853208805511"
+               .. "12540698747158523863050715693290963295227443043557"
+               .. "66896648950445244523161731856403098711121722383113"
+               .. "62229893423380308135336276614282806444486645238749"
+               .. "30358907296290491560440772390713810515859307960866"
+               .. "70172427121883998797908792274921901699720888093776"
+               .. "65727333001053367881220235421809751254540594752243"
+               .. "52584907711670556013604839586446706324415722155397"
+               .. "53697817977846174064955149290862569321978468622482"
+               .. "83972241375657056057490261407972968652414535100474"
+               .. "82166370484403199890008895243450658541227588666881"
+               .. "16427171479924442928230863465674813919123162824586"
+               .. "17866458359124566529476545682848912883142607690042"
+               .. "24219022671055626321111109370544217506941658960408"
+               .. "07198403850962455444362981230987879927244284909188"
+               .. "84580156166097919133875499200524063689912560717606"
+               .. "05886116467109405077541002256983155200055935729725"
+               .. "71636269561882670428252483600823257530420752963450")
+
+        local answer = 0
+
+        for i = 1,(string.len(answer)-13),1
+        do
+            local product = 1
+            for j = 0,12,1
+            do
+                product = product * tonumber(string:sub(j, j))
+            end
+
+            if product > answer
+            then
+                answer = product
+            end
+        end
+
+        return answer
+    end
+}

lua/test.lua

@@ -49,6 +49,7 @@ local problems = {
     ["p0002.lua"] = {4613732, false},
     ["p0004.lua"] = {906609, false},
     ["p0006.lua"] = {25164150, false},
+    ["p0008.lua"] = {23514624000, false},
     ["p0009.lua"] = {31875000, false},
     ["p0017.lua"] = {21124, false},
     ["p0028.lua"] = {669171001, false},