70 lines
1.7 KiB
Nim
70 lines
1.7 KiB
Nim
import tables
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import nre
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import strutils
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let pattern = re"(?<target>\w+)\s(?<opcode>(inc|dec))\s(?<value>-?\d+)\sif\s(?<comptarget>\w+)\s(?<compop>(<|>|==|!=|<=|>=))\s(?<comp2>-?\d+)"
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var registers = initTable[string, int]();
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proc parseLine(li: string): RegexMatch =
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let found = nre.find(li, pattern)
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if found.isNone:
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echo("mismatch")
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return
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return found.get()
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proc compare(target: string, val2: int, op: string): bool =
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# text parsing done right ヽ( ﾟヮ・)ノ
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let val1 = registers[target]
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case op
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of "<":
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return val1 < val2;
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of ">":
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return val1 > val2;
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of "==":
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return val1 == val2;
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of "!=":
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return val1 != val2;
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of "<=":
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return val1 <= val2;
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of ">=":
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return val1 >= val2;
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else: discard
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proc changeRegister(r: string, op: string, val: int): void =
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# only ‘inc’ and ‘dec’ are possible
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if op == "inc":
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registers[r] += val
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else:
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registers[r] -= val
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proc executeLine(ins: Table): void =
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# set registers to 0 if they haven’t been initialized
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if not registers.hasKey(ins["comptarget"]):
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registers[ins["comptarget"]] = 0
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if not registers.hasKey(ins["target"]):
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registers[ins["target"]] = 0
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# do math... or don’t
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if compare(ins["comptarget"], parseInt(ins["comp2"]), ins["compop"]):
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changeRegister(ins["target"], ins["opcode"], parseInt(ins["value"]))
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for line in lines "day8.txt":
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let parsed = parseLine(line)
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executeLine(parsed.captures.toTable())
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# returning a list like with python’s dict.values doesn’t seem to work.
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# is there a way to convert iterables to arrays?
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var maximum = 0
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for v in values(registers):
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if v > maximum:
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maximum = v
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echo(maximum)
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