WIP

hankolsen · hankolsen · commit b97288c7ca2b · 2020-12-16T17:07:56.000+01:00
diff --git a/2020/16/solve.js b/2020/16/solve.js
@@ -18,4 +18,4 @@ const solve2 = () => {
 };
 
 solve1();
-// solve2();
+solve2();
diff --git a/2020/16/test.js b/2020/16/test.js
@@ -1,4 +1,10 @@
-const { util1, util2, isWithinRange, isWithinSomeOfTheRanges } = require('./utils');
+const {
+  util1,
+  util2,
+  isWithinRange,
+  isWithinSomeOfTheRanges,
+  getValidTickets,
+} = require('./utils');
 
 describe('it should solve part 1 and part 2', () => {
   const input1 = [
@@ -16,6 +22,22 @@ describe('it should solve part 1 and part 2', () => {
     '38,6,12',
   ];
 
+  const input2 = [
+    'class: 0-1 or 4-19',
+    'row: 0-5 or 8-19',
+    'seat: 0-13 or 16-19',
+    '',
+    'your ticket:',
+    '11,12,13',
+    '',
+    'nearby tickets:',
+    '3,9,18',
+    '40,4,50',
+    '55,2,20',
+    '15,1,5',
+    '5,14,9',
+  ];
+
   test('it should solve example 1', () => {
     expect(isWithinRange(7, [1, 3, 5, 7])).toEqual(true);
     expect(isWithinRange(3, [1, 3, 5, 7])).toEqual(true);
@@ -42,11 +64,28 @@ describe('it should solve part 1 and part 2', () => {
         [13, 40, 45, 50],
       ]),
     ).toEqual(false);
-    
+
     expect(util1(input1)).toEqual(71);
   });
 
-  /* test('it should solve example 2', () => {
-    expect(util2(input1)).toEqual(0);
-  }); */
+  test('it should solve example 2', () => {
+    util2(input2);
+    const rules = [
+      [0, 1, 4, 19],
+      [0, 5, 8, 19],
+      [0, 13, 16, 19],
+    ];
+    const tickets = [
+      [3, 9, 18],
+      [40, 4, 50],
+      [55, 2, 20],
+      [15, 1, 5],
+      [5, 14, 9],
+    ];
+    expect(getValidTickets(rules, tickets)).toEqual([
+      [3, 9, 18],
+      [15, 1, 5],
+      [5, 14, 9],
+    ]);
+  });
 });
diff --git a/2020/16/utils.js b/2020/16/utils.js
@@ -10,6 +10,18 @@ const parseRules = (input) =>
     })
     .filter(Boolean);
 
+const getRuleNames = (input) =>
+  input
+    .map((row) => {
+      const [, name] =
+        row.match(/(\w+\s?\w+?): (\d+)-(\d+) or (\d+)-(\d+)/) || [];
+      if (name !== undefined) {
+        return name;
+      }
+      return undefined;
+    })
+    .filter(Boolean);
+
 const parseTickets = (input) =>
   input
     .map((row) => {
@@ -52,9 +64,48 @@ const util1 = (input) => {
   return sum;
 };
 
+const getValidTickets = (rules, tickets) =>
+  tickets
+    .map((ticket) => {
+      if (ticket.some((value) => !isWithinSomeOfTheRanges(value, rules))) {
+        return false;
+      }
+      return ticket;
+    })
+    .filter(Boolean);
+
+const findMatchingRules = (rules, tickets, ruleNames) => {
+  const matches = {};
+  tickets.forEach((ticket) => {
+    matches[ticket] = {};
+    rules.forEach((rule, ruleIndex) => {
+      ticket.forEach((value, valueIndex) => {
+        if (isWithinRange(value, rule)) {
+          matches[ticket][ruleNames[valueIndex]] = [
+            ...(matches[ticket][ruleNames[valueIndex]] || []),
+            ruleIndex,
+          ];
+        }
+      });
+    });
+  });
+  return matches;
+};
+
 const util2 = (input) => {
-  console.log(input);
-  return input;
+  const rules = parseRules(input);
+  const [, ...nearbyTickets] = parseTickets(input);
+  const validTickets = getValidTickets(rules, nearbyTickets);
+  const ruleNames = getRuleNames(input);
+  const matchingRules = findMatchingRules(rules, validTickets, ruleNames);
+  Object.values(matchingRules).forEach((matchingRule) => console.log(matchingRule));
+  return validTickets;
 };
 
-module.exports = { util1, util2, isWithinRange, isWithinSomeOfTheRanges };
+module.exports = {
+  util1,
+  util2,
+  isWithinRange,
+  isWithinSomeOfTheRanges,
+  getValidTickets,
+};
