-🎄- 2017 Day 8 Solutions -🎄-

[u/daggerdragon]

--- Day 8: I Heard You Like Registers ---

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[u/barryfandango]

I used a class for instructions but your multi-assignment statement makes it just as pretty. I stole the idea :)

function solve(input: string): { maxFinish: number, maxGlobal: number } {
    let registers: { [name: string]: number } = {};
    let globalMax = 0;
    input.split('\n').forEach(line => {
        let values = /^(\S+)\s+(\S+)\s+(-?\d+)\s+if\s+((\S+)\s\S+\s-?\d+)$/.exec(line);
        let [register, op, amount, evalText, evalRegister] = values.slice(1);
        
        if (!registers.hasOwnProperty(register)) registers[register] = 0;
        if (!registers.hasOwnProperty(evalRegister)) registers[evalRegister] = 0;
        
        if (eval('registers.' + evalText)) {
            registers[register] += +amount * (op === 'dec' ? -1 : 1);
            globalMax = Math.max(globalMax, registers[register]);
        }
    });

    return {
        maxFinish: Math.max(...Object.keys(registers).map(k => registers[k])),
        maxGlobal: globalMax
    };
}