48 lines
1 KiB
JavaScript
48 lines
1 KiB
JavaScript
const fs = require('fs');
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const data = fs.readFileSync('input.txt', 'utf-8');
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const lines = data.split('\n');
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let instructions = [];
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lines.forEach((line, i) => {
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t = line.split(' ');
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instructions[i] = [t[0], parseInt(t[1])]
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})
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function loop (i, seen, acc, swapped) {
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console.log(i, instructions[i])
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if (seen.has(i)) {
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console.log('seen, escaping')
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return false;
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}
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seen.add(i);
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console.log('acc = ', acc)
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let nextI = i;
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let nextAcc = acc;
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switch (instructions[i][0]) {
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case 'acc':
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nextAcc+=instructions[i][1];
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nextI++;
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break;
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case 'jmp':
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nextI += instructions[i][1];
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break;
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case 'nop':
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nextI ++;
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break;
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default:
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console.log('halting with', acc);
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return true;
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}
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nextAcc = loop(nextI, seen, nextAcc, swapped);
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if (nextAcc === false) {
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console.log(i, instructions[i])
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if (instructions[i][0] == 'jmp' && !swapped) {
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nextAcc = loop(i+1, seen, acc, true)
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}
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}
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return nextAcc;
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}
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loop(0, new Set(), 0, false)
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// take the last acc value
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