feat: solve day 7 puzzle 2

README.md

@@ -8,10 +8,10 @@ This project can also be run using the amazing [CraftOS-PC emulator](https://git
 ## Progress
 
 <!-- calendar-start -->
-#### Stars: 0/24
+#### Stars: 14/24
 
 |Mon|Tue|Wed|Thu|Fri|Sat|Sun|
 |:-:|:-:|:-:|:-:|:-:|:-:|:-:|
-|1<br>|2<br>|3<br>|4<br>|5<br>|6<br>|7<br>|
+|1<br>:star::star:|2<br>:star::star:|3<br>:star::star:|4<br>:star::star:|5<br>:star::star:|6<br>:star::star:|7<br>:star::star:|
 |8<br>|9<br>|10<br>|11<br>|12<br>|||
 <!-- calendar-end -->

res/examples/day01.txt

@@ -0,0 +1,10 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82

res/examples/day02.txt

@@ -0,0 +1,3 @@
+11-22,95-115,998-1012,1188511880-1188511890,222220-222224,
+1698522-1698528,446443-446449,38593856-38593862,565653-565659,
+824824821-824824827,2121212118-2121212124

res/examples/day03.txt

@@ -0,0 +1,4 @@
+987654321111111
+811111111111119
+234234234234278
+818181911112111

res/examples/day04.txt

@@ -0,0 +1,10 @@
+..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.

res/examples/day05.txt

@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32

res/examples/day06.txt

@@ -0,0 +1,4 @@
+123 328  51 64 
+ 45 64  387 23 
+  6 98  215 314
+*   +   *   +  

res/examples/day07.txt

@@ -0,0 +1,16 @@
+.......S.......
+...............
+.......^.......
+...............
+......^.^......
+...............
+.....^.^.^.....
+...............
+....^.^...^....
+...............
+...^.^...^.^...
+...............
+..^...^.....^..
+...............
+.^.^.^.^.^...^.
+...............

res/stats.json

@@ -1,31 +1,31 @@
 {
     "day01": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day02": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day03": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day04": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day05": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day06": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day07": {
-        "puzzle1": false,
+        "puzzle1": true,
-        "puzzle2": false
+        "puzzle2": true
     },
     "day08": {
         "puzzle1": false,

src/day01/puzzle1.lua

@@ -0,0 +1,25 @@
+local utils = require "utils"
+local puzzle1 = {}
+
+function puzzle1.solve(input)
+    local password = 0
+    local cursor = 50
+    
+    local lines = utils.splitLines(input)
+    for _, line in ipairs(lines) do
+        local dir = line:sub(1, 1)
+        local dist = tonumber(line:sub(2))
+        if dir == "R" then
+            cursor = cursor + dist
+        else
+            cursor = cursor - dist
+        end
+        cursor = cursor % 100
+        if cursor == 0 then
+            password = password + 1
+        end
+    end
+    return password
+end
+
+return puzzle1

src/day01/puzzle2.lua

@@ -0,0 +1,31 @@
+local utils = require "utils"
+local puzzle2 = {}
+
+function puzzle2.solve(input)
+    local password = 0
+    local cursor = 50
+    
+    local lines = utils.splitLines(input)
+    for _, line in ipairs(lines) do
+        local dir = line:sub(1, 1)
+        local dist = tonumber(line:sub(2))
+        if dir == "R" then
+            cursor = cursor + dist
+            if cursor > 99 then
+                password = password + math.floor(cursor / 100)
+            end
+        else
+            cursor = cursor - dist
+            if cursor <= 0 then
+                if cursor ~= -dist then
+                    password = password + 1
+                end
+                password = password + math.floor(-cursor / 100)
+            end
+        end
+        cursor = cursor % 100
+    end
+    return password
+end
+
+return puzzle2

src/day02/puzzle1.lua

@@ -0,0 +1,38 @@
+local utils = require "utils"
+local puzzle1 = {}
+
+function puzzle1.splitRange(range)
+    local parts = utils.split(range, "-")
+    return tonumber(parts[1]), tonumber(parts[2])
+end
+
+function puzzle1.isValid(id)
+    local str = tostring(id)
+    if #str % 2 == 1 then
+        return true
+    end
+    local mid = #str / 2
+    return str:sub(1, mid) ~= str:sub(mid + 1)
+end
+
+function puzzle1.countInvalids(range)
+    local min, max = puzzle1.splitRange(range)
+    local total = 0
+    for i=min, max do
+        if not puzzle1.isValid(i) then
+            total = total + i
+        end
+    end
+    return total
+end
+
+function puzzle1.solve(input)
+    local ranges = utils.split(input, ",")
+    local total = 0
+    for _, range in ipairs(ranges) do
+        total = total + puzzle1.countInvalids(range)
+    end
+    return total
+end
+
+return puzzle1

src/day02/puzzle2.lua

@@ -0,0 +1,46 @@
+local utils = require "utils"
+local puzzle1 = require(SRC_PATH .. "/day02/puzzle1")
+local puzzle2 = {}
+
+function puzzle2.isValid(id)
+    local str = tostring(id)
+    local totLen = #str
+    for len=1, totLen - 1 do
+        if totLen % len == 0 then
+            local ref = str:sub(1, len)
+            local allSame = true
+            for i=1, totLen / len - 1 do
+                if str:sub(len * i + 1, len * (i + 1)) ~= ref then
+                    allSame = false
+                    break
+                end
+            end
+            if allSame then
+                return false
+            end
+        end
+    end
+    return true
+end
+
+function puzzle2.countInvalids(range)
+    local min, max = puzzle1.splitRange(range)
+    local total = 0
+    for i=min, max do
+        if not puzzle2.isValid(i) then
+            total = total + i
+        end
+    end
+    return total
+end
+
+function puzzle2.solve(input)
+    local ranges = utils.split(input, ",")
+    local total = 0
+    for _, range in ipairs(ranges) do
+        total = total + puzzle2.countInvalids(range)
+    end
+    return total
+end
+
+return puzzle2

src/day03/puzzle1.lua

@@ -0,0 +1,41 @@
+local utils = require("utils")
+local puzzle1 = {}
+
+function puzzle1.bankJoltages(bank)
+    local joltages = {}
+    for i=1, #bank do
+        table.insert(joltages, tonumber(bank:sub(i, i)))
+    end
+    return joltages
+end
+
+function puzzle1.findMaxJoltage(bank)
+    local maxTens = 0
+    local maxJoltage = 0
+    local joltages = puzzle1.bankJoltages(bank)
+
+    for i, tens in ipairs(joltages) do
+        if tens > maxTens then
+            for j=i+1, #joltages do
+                local ones = joltages[j]
+                local joltage = tens * 10 + ones
+                if joltage > maxJoltage then
+                    maxTens = tens
+                    maxJoltage = joltage
+                end
+            end
+        end
+    end
+    return maxJoltage
+end
+
+function puzzle1.solve(input)
+    local banks = utils.splitLines(input)
+    local totalJoltage = 0
+    for _, bank in ipairs(banks) do
+        totalJoltage = totalJoltage + puzzle1.findMaxJoltage(bank)
+    end
+    return totalJoltage
+end
+
+return puzzle1

src/day03/puzzle2.lua

@@ -0,0 +1,64 @@
+local utils = require("utils")
+local puzzle1 = require(SRC_PATH .. "/day03/puzzle1")
+local puzzle2 = {}
+
+local cache = {}
+
+function puzzle2.findMaxJoltage(bank, joltages, n, startI)
+    startI = startI or 1
+    local key = bank:sub(startI) .. "-" .. tostring(n)
+    if cache[key] then
+        return cache[key]
+    end
+
+    local maxJoltage = 0
+    local maxDigit = 0
+
+    if startI > #joltages then
+        return nil
+    end
+
+    if n == 1 then
+        for i=startI, #joltages do
+            if joltages[i] > maxDigit then
+                maxDigit = joltages[i]
+            end
+        end
+        cache[key] = maxDigit
+        return maxDigit
+    end
+
+    local i = startI
+    while i <= #joltages do
+        local digit = joltages[i]
+        if digit > maxDigit then
+            local maxSuffix = puzzle2.findMaxJoltage(bank, joltages, n - 1, i + 1)
+            if maxSuffix ~= nil then
+                local joltage = tonumber(tostring(digit) .. tostring(maxSuffix))
+                if joltage > maxJoltage then
+                    maxDigit = digit
+                    maxJoltage = joltage
+                end
+            end
+        end
+        i = i + 1
+    end
+    if maxJoltage == 0 then
+        return nil
+    end
+    cache[key] = maxJoltage
+    return maxJoltage
+end
+
+function puzzle2.solve(input)
+    local banks = utils.splitLines(input)
+    local totalJoltage = 0
+    for _, bank in ipairs(banks) do
+        local joltages = puzzle1.bankJoltages(bank)
+        local max = puzzle2.findMaxJoltage(bank, joltages, 12)
+        totalJoltage = totalJoltage + max
+    end
+    return totalJoltage
+end
+
+return puzzle2

src/day04/puzzle1.lua

@@ -0,0 +1,44 @@
+local utils = require "utils"
+
+local puzzle1 = {}
+
+function puzzle1.inGrid(x, y, w, h)
+    return 1 <= x and x <= w and 1 <= y and y <= h
+end
+
+function puzzle1.isAccessible(lines, w, h, x, y)
+    local neighbors = 0
+    for dy=-1, 1 do
+        for dx=-1, 1 do
+            if dx ~=0 or dy ~= 0 then
+                local x2 = x + dx
+                local y2 = y + dy
+                if puzzle1.inGrid(x2, y2, w, h) then
+                    if lines[y2]:sub(x2, x2) == "@" then
+                        neighbors = neighbors + 1
+                    end
+                end
+            end
+        end
+    end
+    return neighbors < 4
+end
+
+function puzzle1.solve(input)
+    local lines = utils.splitLines(input)
+    local accessible = 0
+
+    local h = #lines
+    local w = #lines[1]
+
+    for y, line in ipairs(lines) do
+        for x=1, #line do
+            if line:sub(x, x) == "@" and puzzle1.isAccessible(lines, w, h, x, y) then
+                accessible = accessible + 1
+            end
+        end
+    end
+    return accessible
+end
+
+return puzzle1

src/day04/puzzle2.lua

@@ -0,0 +1,106 @@
+local utils = require "utils"
+
+local puzzle2 = {}
+
+function puzzle2.inGrid(x, y, w, h)
+    return 1 <= x and x <= w and 1 <= y and y <= h
+end
+
+function puzzle2.countNeighbors(lines, w, h, x, y)
+    local neighbors = 0
+    for dy=-1, 1 do
+        for dx=-1, 1 do
+            if dx ~=0 or dy ~= 0 then
+                local x2 = x + dx
+                local y2 = y + dy
+                if puzzle2.inGrid(x2, y2, w, h) then
+                    if lines[y2]:sub(x2, x2) == "@" then
+                        neighbors = neighbors + 1
+                    end
+                end
+            end
+        end
+    end
+    return neighbors
+end
+
+function puzzle2.copyGrid(grid)
+    local grid2 = {}
+    for y, row in ipairs(grid) do
+        local row2 = {}
+        for x, n in ipairs(row) do
+            row2[x] = n
+        end
+        grid2[y] = row2
+    end
+    return grid2
+end
+
+function puzzle2.removeRoll(grid, x, y, w, h)
+    for dy=-1, 1 do
+        for dx=-1, 1 do
+            if dx ~= 0 or dy ~= 0 then
+                local x2 = x + dx
+                local y2 = y + dy
+                if puzzle2.inGrid(x2, y2, w, h) then
+                    if grid[y2][x2] > 0 then
+                        grid[y2][x2] = grid[y2][x2] - 1
+                    end
+                end
+            end
+        end
+    end
+    grid[y][x] = -1
+end
+
+function puzzle2.removeRolls(grid, w, h)
+    local removed = 0
+    local grid2 = puzzle2.copyGrid(grid)
+
+    for y, row in ipairs(grid) do
+        for x, n in ipairs(row) do
+            if 0 <= n and n < 4 then
+                puzzle2.removeRoll(grid2, x, y, w, h)
+                removed = removed + 1
+            end
+        end
+    end
+
+    return removed, grid2
+end
+
+function puzzle2.solve(input)
+    local lines = utils.splitLines(input)
+
+    local h = #lines
+    local w = #lines[1]
+
+    local grid = {}
+
+    for y, line in ipairs(lines) do
+        local row = {}
+        for x=1, #line do
+            local neighbors = -1
+            if line:sub(x, x) == "@" then
+                neighbors = puzzle2.countNeighbors(lines, w, h, x, y)
+            end
+            row[x] = neighbors
+        end
+        grid[y] = row
+    end
+
+    local totalRemoved = 0
+
+    local removed = 0
+    while true do
+        removed, grid = puzzle2.removeRolls(grid, w, h)
+        if removed == 0 then
+            break
+        end
+        totalRemoved = totalRemoved + removed
+    end
+
+    return totalRemoved
+end
+
+return puzzle2

src/day05/puzzle1.lua

@@ -0,0 +1,39 @@
+local strings = require "cc.strings"
+local puzzle1 = {}
+
+function puzzle1.isFresh(ranges, i)
+    for _, range in ipairs(ranges) do
+        if range[1] <= i and i <= range[2] then
+            return true
+        end
+    end
+    return false
+end
+
+function puzzle1.solve(input)
+    local lines = strings.split(input, "\n")
+    local ranges = {}
+
+    local bIngr = false
+    local totalFresh = 0
+
+    for _, line in ipairs(lines) do
+        if line == "" then
+            bIngr = true
+        else
+            if bIngr then
+                local ingr = tonumber(line)
+                if puzzle1.isFresh(ranges, ingr) then
+                    totalFresh = totalFresh + 1
+                end
+            else
+                local min, max = line:match("(%d+)%-(%d+)")
+                table.insert(ranges, {tonumber(min), tonumber(max)})
+            end
+        end
+    end
+
+    return totalFresh
+end
+
+return puzzle1

src/day05/puzzle2.lua

@@ -0,0 +1,47 @@
+local strings = require "cc.strings"
+local puzzle2 = {}
+
+function puzzle2.solve(input)
+    local lines = strings.split(input, "\n")
+    local bounds = {}
+
+    for _, line in ipairs(lines) do
+        if line == "" then
+            break
+        end
+        local min, max = line:match("(%d+)%-(%d+)")
+        min = tonumber(min)
+        max = tonumber(max)
+        table.insert(bounds, {i=min, type="start"})
+        table.insert(bounds, {i=max, type="end"})
+    end
+
+    table.sort(bounds, function (a, b)
+        if a.i == b.i then
+            return a.type == "start" and b.type == "end"
+        end
+        return a.i < b.i
+    end)
+
+    local totalFresh = 0
+    local min = 0
+    local balance = 0
+
+    for _, bound in ipairs(bounds) do
+        if bound.type == "start" then
+            if balance == 0 then
+                min = bound.i
+            end
+            balance = balance + 1
+        else
+            balance = balance - 1
+            if balance == 0 then
+                totalFresh = totalFresh + bound.i - min + 1
+            end
+        end
+    end
+
+    return totalFresh
+end
+
+return puzzle2

src/day06/puzzle1.lua

@@ -0,0 +1,39 @@
+local strings = require "cc.strings"
+local puzzle1 = {}
+
+function puzzle1.solve(input)
+    local lines = strings.split(input, "\n")
+    local problems = {}
+    local n = #lines
+
+    local ops = strings.split(lines[n], "%s+")
+
+    for i, line in ipairs(lines) do
+        local j = 1
+        for num in line:gmatch("(%d+)") do
+            local op = ops[j]
+            if i == 1 then
+                if op == "+" then
+                    table.insert(problems, 0)
+                else
+                    table.insert(problems, 1)
+                end
+            end
+            local val = tonumber(num)
+            if op == "+" then
+                problems[j] = problems[j] + val
+            else
+                problems[j] = problems[j] * val
+            end
+            j = j + 1
+        end
+    end
+
+    local total = 0
+    for _, val in ipairs(problems) do
+        total = total + val
+    end
+    return total
+end
+
+return puzzle1

src/day06/puzzle2.lua

@@ -0,0 +1,58 @@
+local strings = require "cc.strings"
+local puzzle2 = {}
+
+function puzzle2.parseNumbers(lines)
+    local numbers = {}
+    local n = #lines
+
+    for i, line in ipairs(lines) do
+        if i ~= n then
+            for j=1, #line do
+                local c = line:sub(j, j)
+                if #numbers < j then
+                    table.insert(numbers, {})
+                end
+                if c ~= " " then
+                    table.insert(numbers[j], c)
+                end
+            end
+        end
+    end
+
+    local problems = {{}}
+    for _, num in ipairs(numbers) do
+        if #num == 0 then
+            table.insert(problems, {})
+        else
+            local value = tonumber(table.concat(num, ""))
+            table.insert(problems[#problems], value)
+        end
+    end
+    return problems
+end
+
+function puzzle2.solve(input)
+    local lines = strings.split(input, "\n")
+    local values = puzzle2.parseNumbers(lines)
+    local ops = strings.split(lines[#lines], "%s+")
+
+    local total = 0
+    for p, numbers in ipairs(values) do
+        local op = ops[p]
+        local value = 0
+        if op == "*" then
+            value = 1
+        end
+        for _, num in ipairs(numbers) do
+            if op == "+" then
+                value = value + num
+            else
+                value = value * num
+            end
+        end
+        total = total + value
+    end
+    return total
+end
+
+return puzzle2

src/day07/puzzle1.lua

@@ -0,0 +1,34 @@
+local utils = require "utils"
+
+local puzzle1 = {}
+
+function puzzle1.solve(input)
+    local lines = utils.splitLines(input)
+
+    local beams = {}
+    local totalSplits = 0
+
+    for i, line in ipairs(lines) do
+        local newBeams = {}
+        if i == 1 then
+            newBeams[line:find("S")] = true
+        else
+            for j=1, #line do
+                if beams[j] then
+                    if line:sub(j, j) == "^" then
+                        totalSplits = totalSplits + 1
+                        newBeams[j - 1] = true
+                        newBeams[j + 1] = true
+                    else
+                        newBeams[j] = true
+                    end
+                end
+            end
+        end
+        beams = newBeams
+    end
+
+    return totalSplits
+end
+
+return puzzle1

src/day07/puzzle2.lua

@@ -0,0 +1,37 @@
+local utils = require "utils"
+
+local puzzle2 = {}
+
+function puzzle2.solve(input)
+    local lines = utils.splitLines(input)
+
+    local beams = {}
+
+    for i, line in ipairs(lines) do
+        local newBeams = {}
+        if i == 1 then
+            newBeams[line:find("S")] = 1
+        else
+            for j=1, #line do
+                if beams[j] then
+                    if line:sub(j, j) == "^" then
+                        newBeams[j - 1] = (newBeams[j - 1] or 0) + beams[j]
+                        newBeams[j + 1] = (newBeams[j + 1] or 0) + beams[j]
+                    else
+                        newBeams[j] = (newBeams[j] or 0) + beams[j]
+                    end
+                end
+            end
+        end
+        beams = newBeams
+    end
+
+    local finalBeams = 0
+    for _, v in pairs(beams) do
+        finalBeams = finalBeams + v
+    end
+
+    return finalBeams
+end
+
+return puzzle2

src/lib/days.lua

@@ -147,7 +147,7 @@ function Day:execPuzzle(puzzleI, data, resultKey)
     local result = puzzle.solve(data)
     local t1 = os.epoch("local")
     print(("(Executed in %.3fs)"):format((t1 - t0) / 1000))
-    print("Result:", result)
+    print(("Result: %.0f"):format(result))
     self.results[resultKey] = result
     self:saveResults()
 end

src/lib/utils.lua

@@ -78,14 +78,18 @@ function utils.waitForKey(targetKey)
     end
 end
 
-function utils.splitLines(data)
+function utils.split(data, sep)
     local t = {}
-    for str in string.gmatch(data, "([^\n]+)") do
+    for str in string.gmatch(data, "([^" .. sep .. "]+)") do
         table.insert(t, str)
     end
     return t
 end
 
+function utils.splitLines(data)
+    return utils.split(data, "\n")
+end
+
 function utils.round(x)
     return x >= 0 and math.floor(x + 0.5) or math.ceil(x - 0.5)
 end