82 lines
1.9 KiB
JavaScript
82 lines
1.9 KiB
JavaScript
const fs = require('fs');
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const inputArray = fs.readFileSync('input.txt').toString().split("\n");
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const heights = [];
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for (const line of inputArray) {
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const lineArray = line.split("").map(Number);
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heights.push(lineArray);
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}
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// Day One
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const lows = [];
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for (const row in heights) {
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for (const column in heights[row]) {
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const above = parseInt(row)-1;
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const below = parseInt(row)+1;
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const left = parseInt(column)-1;
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const right = parseInt(column)+1;
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let highs = 0;
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if (above === -1 || (heights[above][column] > heights[row][column])) highs++; // above
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if (below === heights.length || (heights[below][column] > heights[row][column])) highs++; // below
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if (left === -1 || (heights[row][left] > heights[row][column])) highs++; // left
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if (right === heights[row].length || (heights[row][right] > heights[row][column])) highs++; // right
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if (highs === 4) {
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lows.push(heights[row][column])
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}
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}
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}
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const risk = lows.reduce((a, b) => a + b, 0) + lows.length;
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console.log(risk)
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// Day Two
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for (const row in heights) {
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for (const column in heights[row]) {
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if (heights[row][column] !== 9) heights[row][column] = 0;
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}
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}
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const visited = [];
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const basins = [];
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function inBasin (row, column) {
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if (visited.includes(`${row},${column}`))
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return 0;
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else {
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visited.push(`${row},${column}`)
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}
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if (row < 0 || row >= heights.length) {
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return 0;
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}
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if (column < 0 || column >= heights[0].length) {
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return 0;
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}
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if (heights[row][column] === 9) {
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return 0;
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}
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let size = 1;
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size += inBasin(row - 1, column);
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size += inBasin(row + 1, column);
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size += inBasin(row, column - 1);
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size += inBasin(row, column + 1);
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return size;
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}
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for (const row in heights) {
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for (const column in heights[row]) {
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const size = inBasin(parseInt(row), parseInt(column));
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if (size > 0) {
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basins.push(size)
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}
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}
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}
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basins.sort((a,b) => b - a);
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console.log(basins[0] * basins[1] * basins[2]);
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