advent-of-code/2022/8/index2.js

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2022-12-08 19:06:34 +00:00
const fs = require('fs/promises');
let answer = 0;
const rotate90 = (matrix) => {
const result = matrix[matrix.length - 1].map(x => [x]) ;
for (const row of (matrix.slice(0, -1).reverse())) {
for(const [i, columns] of result.entries()) {
columns.push(row[i]);
}
};
return result;
}
const getScenicScore = (matrix, rotatedMatrix, x, y) => {
const height = matrix[y][x];
const rY = x;
const rX = matrix.length - y - 1;
const left = matrix[y].slice(0, x).reverse();
const right = matrix[y].slice(x + 1);
const bottom = rotatedMatrix[rY].slice(0, rX).reverse();
const top = rotatedMatrix[rY].slice(rX + 1);
const directions = [left, right, bottom, top];
return directions.map(trees => {
const distance = trees.findIndex(tree => tree >= height) + 1;
return distance || trees.length;
}).reduce((product, score) => score * product, 1);
};
//1234
//5678
//9012
const countVisible = (matrix) => {
return matrix.reduce((count, row) => {
const [_, rowCount] = row.reduce(([tallest, count], tree) => {
return [Math.max(tree, tallest), tree > tallest ? count+1: count];
}, [-1, 0]);
return count + rowCount;
},0);
}
(async () => {
const input = await fs.readFile("./input.txt", 'utf8');
//const input = "1234\n5678\n9012";
const lines = input.split("\n");
const matrix = lines.map(line => line.split("").map(x => parseFloat(x))).filter(x => x.length);
const rotatedMatrix = rotate90(matrix);
for(let y = 0; y < matrix.length; ++y) {
for(let x = 0; x < matrix[0].length; ++x) {
const score = getScenicScore(matrix, rotatedMatrix, x, y);
answer = Math.max(answer, score);
}
}
console.log(answer);
})();