solve Day03 in TS

Day03/ts/solution.ts

@@ -0,0 +1,97 @@
+import { readFileSync } from 'fs';
+import { resolve } from 'path';
+
+function parseSchematic(filePath: string): string[] {
+    try {
+        const data = readFileSync(filePath, 'utf8');
+        return data.split('\n').map(line => line.trim());
+    } catch (err) {
+        throw new Error(`Error reading file: ${filePath}, ${(err as Error).message}`);
+    }
+}
+
+function getAdjacentPositions(rows: number, cols: number, row: number, col: number): [number, number][] {
+    const positions: [number, number][] = [];
+    for (let i = Math.max(0, row - 1); i <= Math.min(rows - 1, row + 1); i++) {
+        for (let j = Math.max(0, col - 1); j <= Math.min(cols - 1, col + 1); j++) {
+            if (i !== row || j !== col) {
+                positions.push([i, j]);
+            }
+        }
+    }
+    return positions;
+}
+
+function findStartOfNumber(schematic: string[], row: number, col: number): number {
+    while (col > 0 && /\d/.test(schematic[row][col - 1])) {
+        col--;
+    }
+    return col;
+}
+
+function extractFullNumber(schematic: string[], startRow: number, startCol: number): number {
+    let col = findStartOfNumber(schematic, startRow, startCol);
+    let number = '';
+    
+    while (col < schematic[startRow].length && /\d/.test(schematic[startRow][col])) {
+        number += schematic[startRow][col];
+        schematic[startRow] = schematic[startRow].substring(0, col) + '.' + schematic[startRow].substring(col + 1);
+        col++;
+    }
+
+    return parseInt(number, 10);
+}
+
+function findGearsAndCalculateRatios(schematic: string[]): number {
+    const rows = schematic.length;
+    const cols = schematic[0].length;
+    let totalRatioSum = 0;
+
+    for (let row = 0; row < rows; row++) {
+        for (let col = 0; col < cols; col++) {
+            if (schematic[row][col] === '*') {
+                const partNumbers: number[] = [];
+                for (const [i, j] of getAdjacentPositions(rows, cols, row, col)) {
+                    if (/\d/.test(schematic[i][j])) {
+                        const partNumber = extractFullNumber(schematic, i, j);
+                        if (!partNumbers.includes(partNumber)) {
+                            partNumbers.push(partNumber);
+                        }
+                    }
+                }
+
+                if (partNumbers.length === 2) {
+                    const gearRatio = partNumbers[0] * partNumbers[1];
+                    totalRatioSum += gearRatio;
+                    console.log(`Found gear at line ${row + 1} with ratio ${gearRatio}`);
+                }
+            }
+        }
+    }
+
+    return totalRatioSum;
+}
+
+function runTest() {
+    const testFilePath = resolve(__dirname, '../test.txt');
+    const testSchematic = parseSchematic(testFilePath);
+    const testResult = findGearsAndCalculateRatios(testSchematic);
+    console.log(`Test Result: ${testResult}`);
+    console.assert(testResult === 467835, `Test failed: Expected 467835, got ${testResult}`);
+}
+
+function main() {
+    try {
+        runTest();
+        console.log("Test passed successfully.");
+
+        const inputFilePath = resolve(__dirname, '../input.txt');
+        const inputSchematic = parseSchematic(inputFilePath);
+        const totalRatioSum = findGearsAndCalculateRatios(inputSchematic);
+        console.log(`Total sum of gear ratios: ${totalRatioSum}`);
+    } catch (error) {
+        console.error((error as Error).message);
+    }
+}
+
+main();