96 lines
2 KiB
TypeScript
96 lines
2 KiB
TypeScript
enum LogLevel {
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Answer,
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Info,
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Debug,
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}
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const LOG_LEVEL = LogLevel.Debug;
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const print = (level: keyof typeof LogLevel, msg: string) => {
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if (LogLevel[level] <= LOG_LEVEL) {
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console.log(level+': '+msg);
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}
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}
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const file = Bun.file("input.txt");
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const input = await file.text();
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function* findGears (schematic: string[]) {
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const matcher = /\*/g;
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for (const i in schematic) {
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const line = schematic[i];
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for (let res = matcher.exec(line); res !== null; res = matcher.exec(line)) {
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const index = matcher.lastIndex - 1;
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const end = matcher.lastIndex - 1;
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print('Debug',`[${Number(i)+1},${index+1}]`);
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yield {
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line: Number(i),
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index,
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};
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}
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}
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}
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interface Match {
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line: number,
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index: number,
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}
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function neighbours (schematic: string[], match: Match): number[] {
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const lastCol = schematic[0].length - 1;
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const lastRow = schematic.length - 1;
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function inbounds(x,y) {
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return x >= 0 && y >= 0 && x <= lastCol && y <= lastRow;
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}
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const matches = [];
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for (let y of [match.line-1, match.line, match.line+1]) {
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let left = match.index-1;
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while (inbounds(left,y) && /[0-9]/.test(schematic[y][left])) {
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left--;
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};
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left = Math.max(left, 0);
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let right = match.index+1;
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while (inbounds(right,y) && /[0-9]/.test(schematic[y][right])) {
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right++;
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};
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right = Math.min(right, lastCol+1);
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const substr = schematic[y].slice(left,right);
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const matcher = /[0-9]+/g;
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for (let res = matcher.exec(substr); res !== null; res = matcher.exec(substr)) {
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matches.push(...res)
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}
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}
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print('Debug', `neighbours: ${matches}`);
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return matches.map(Number);
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}
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function main(): void {
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const lines = input.trim().split("\n");
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for (const line of lines) {
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print('Info', line);
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}
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let total = 0;
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for (const match of findGears(lines)) {
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const nums = neighbours(lines,match)
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if (nums.length === 2) {
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const ratio = nums[0] * nums[1];
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print('Debug', `adding ${ratio}`);
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total += ratio;
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}
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}
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print('Answer', total);
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}
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main();
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// too low: 83445843
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