36 lines
906 B
JavaScript
36 lines
906 B
JavaScript
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const fs = require('fs');
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const input = fs.readFileSync('./part1input.txt', 'utf-8');
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let rules = new Map();
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input.split('\n\n')[0].split('\n').forEach(line => {
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parts = line.split(': ');
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rules.set(parts[0], parts[1].split(' | ').map(o => o.split(' ')));
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});
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let howFar = 0;
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function check (str, ruleNum = '0', matchToEnd = true) {
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if (ruleNum[0] == '"') {
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return str[howFar++] == ruleNum[1];
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}
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let rule = rules.get(ruleNum);
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for (let pattern of rule) {
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let before = howFar;
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let success = true;
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for (let token of pattern) {
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let match = check(str, token, false);
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if (!match) {
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success = false;
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break;
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}
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}
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if (matchToEnd?success&&howFar==str.length:success) return true;
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howFar = before
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}
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return false;
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}
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let total = 0
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input.split('\n\n')[1].split('\n').forEach(line => {
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howFar = 0
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total+=check(line)
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});
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console.log(total)
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