day23.part1.js

// -*- node.jz -*-

let input = ''
process.stdin.on('readable', () => input += process.stdin.read() || '')
process.stdin.on('end', () => main())

const EventEmitter = require('events')

class Program extends EventEmitter {
    constructor(id) {
        super()
        this.id = 0
        this.stack = {}
        this.i = 0
    }

    load(programStr) {
        this.instructions = programStr
        .split('\n')
        .map(line => line.split(/\s/))
    }

    next() {
        let i = this.i
        const [op, arg1, arg2] = this.instructions[i]
        const valArg1 = this.stack[arg1] || parseInt(arg1) || 0
        const valArg2 = this.stack[arg2] || parseInt(arg2) || 0
        switch (op) {
        case 'set':
            this.stack[arg1] = valArg2
            i += 1
            break
        case 'sub':
            this.stack[arg1] = valArg1 - valArg2
            i += 1
            break
        case 'mul':
            this.emit('mul')
            this.stack[arg1] = valArg1 * valArg2
            i += 1
            break
        case 'jnz':
            if (valArg1 !== 0)
                i += valArg2
            else
                i += 1
            break
        }

        this.i = i
    }

    run() {
        while (this.i >= 0 && this.i < this.instructions.length) {
            this.next()
        }
        this.emit('end')
    }
}

function main() {
    const zero = new Program(0)
    let mulcount = 0
    zero.on('mul', () => {
        mulcount++
    })
    zero.on('end', () => {
        console.log(`Multiplies: ${mulcount}`)
    })
    zero.load(input)
    zero.run()
}

day23.part2.__ir__.js

    b = 57
    c = b
    // jnz a 2
    // jnz 1 5
    b *= 100
    b -= -100000
    c = b
    c -= -17000
    do { f = 1
        d = 2
        do { e = 2
            do { g = d
                g *= e
                g -= b
                if (g === 0)
                    f = 0
                e -= -1
                g = e
                g -= b
            } while (g !== 0)
            d -= -1
            g = d
            g -= b
        } while (g !== 0)
        if (f === 0)
            h -= -1
        g = b
        g -= c
        if (g === 0)
            process.exit()
        b -= -17
    } while (true)

day23.part2.c

#include <stdio.h>

int main() {
    int a = 1;
    int b, c, d, e, f, g, h;
    b = c = d = e = f = g = h = 0;

    b = 105700;
    c = b + 17000;
    for (; b <= c; b += 17) {
        f = 1;
        for (d = 2; d <= b/2; d++) {
            if (b % d == 0) {
                f = 0;
            }
        }
        if (f == 0) {
            h += 1;
        }
    }

    printf("h: %d\n", h);
    return 0;
}