2023.01

challenges/2023/01.js

@@ -0,0 +1,99 @@
+// Part 1
+const solvePuzzle1 = (input) => {
+  let sum = 0;
+
+  input.split('\n').forEach((line) => {
+    let numbers = [null, null];
+
+    // Find the first number
+    for (let i = 0; i < line.length; i++) {
+      if (!isNaN(Number(line[i]))) {
+        numbers[0] = line[i];
+        break;
+      }
+    }
+
+    // Find the last number
+    for (let i = line.length - 1; i >= 0; i--) {
+      if (!isNaN(Number(line[i]))) {
+        numbers[1] = line[i];
+        break;
+      }
+    }
+
+    sum += Number(numbers.join(''));
+  });
+
+  return sum;
+};
+
+// Part 2
+const solvePuzzle2 = (input) => {
+  let sum = 0;
+
+  const numberStrings = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine'];
+  const numberPatterns = [/one/g, /two/g, /three/g, /four/g, /five/g, /six/g, /seven/g, /eight/g, /nine/g];
+
+  input.split('\n').forEach((line) => {
+    // Find `String` numbers
+    const stringNumbers = [null, null];
+    const stringNumberIndexes = [line.length - 1, 0];
+
+    // Match each number pattern individually because if we have a `twone`
+    // the `one` will not match after `two` is already matched
+    numberPatterns.forEach((pattern) => {
+      [...line.matchAll(pattern)].forEach((match) => {
+        match.lastIndex = match.index + match[0].length;
+
+        if (match.index < stringNumberIndexes[0]) {
+          stringNumberIndexes[0] = match.index;
+          stringNumbers[0] = numberStrings.indexOf(match[0]).toString();
+        }
+
+        if (match.lastIndex > stringNumberIndexes[1]) {
+          stringNumberIndexes[1] = match.lastIndex;
+          stringNumbers[1] = numberStrings.indexOf(match[0]).toString();
+        }
+      });
+    });
+
+    // Find `Number` numbers
+    let numbers = [null, null];
+    let numberIndexes = [line.length - 1, 0];
+
+    // Find the first `Number` number and its index
+    for (let i = 0; i < line.length; i++) {
+      if (!isNaN(Number(line[i]))) {
+        numbers[0] = line[i];
+        numberIndexes[0] = i;
+        break;
+      }
+    }
+
+    // Find the last `Number` number and its index
+    for (let i = line.length - 1; i >= 0; i--) {
+      if (!isNaN(Number(line[i]))) {
+        numbers[1] = line[i];
+        numberIndexes[1] = i;
+        break;
+      }
+    }
+
+    // Choose the first number from `String` or `Number` number, whichever comes first
+    if (stringNumberIndexes[0] < numberIndexes[0]) {
+      numbers[0] = stringNumbers[0];
+    }
+
+    // Choose the last number from `String` or `Number` number, whichever comes last
+    if (stringNumberIndexes[1] > numberIndexes[1]) {
+      numbers[1] = stringNumbers[1];
+    }
+
+    sum += Number(numbers.join(''));
+  });
+
+  return sum;
+};
+
+require(__dirname + '/../../utils/test.js').test(__filename, __dirname, solvePuzzle1, '1');
+require(__dirname + '/../../utils/test.js').test(__filename, __dirname, solvePuzzle2, '2');