diff options
Diffstat (limited to '03.lua')
| -rw-r--r-- | 03.lua | 65 |
1 files changed, 65 insertions, 0 deletions
@@ -0,0 +1,65 @@ +local function parse_instruction (x, y, dont) + if dont then return 'dont' + elseif x then return {'mul', tonumber(x), tonumber(y)} + else return 'do' + end +end + +local function input () + local line = '' + local start, next_mul, next_do = 1, 0, 0 + return function () + while true do + if next_mul and next_mul < start then + next_mul = string.find(line, 'mul', start) + end + if next_do and next_do < start then + next_do = string.find(line, 'do', start) + end + if next_mul and (not next_do or next_mul < next_do) then + start = next_mul + 1 + local x, y = string.match(line, '^mul%((%d+),(%d+)%)', next_mul) + if x then return 'mul', tonumber(x), tonumber(y) end + elseif next_do and (not next_mul or next_do < next_mul) then + start = next_do + 1 + if string.match(line, '^do%(%)', next_do) then + return 'do' + elseif string.match(line, "^don't%(%)", next_do) then + return 'dont' + end + elseif not next_mul and not next_do then + line = io.read '*l' + if not line then return end + start, next_mul, next_do = 1, 0, 0 + end + end + end +end + +local funcs = {reader = input()} + +function funcs:part1 () + local sum = 0 + for op, arg1, arg2 in self.reader do + if op == 'mul' then sum = sum + arg1 * arg2 end + end + print(sum) +end + +function funcs:part2() + local sum = 0 + local enabled = true + for op, arg1, arg2 in self.reader do + print(op, arg1, arg2) + if op == 'do' then + enabled = true + elseif op == 'dont' then + enabled = false + elseif op == 'mul' then + if enabled then sum = sum + arg1 * arg2 end + end + end + print(sum) +end + +return funcs |