103 lines
3.8 KiB
JavaScript
103 lines
3.8 KiB
JavaScript
import { readFileSync } from "fs";
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const input = readFileSync("heightmap.txt", "utf-8");
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function BFS(map, visited = [], toCheck = [], endingPos, dimensions) {
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const whereFrom = {};
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whereFrom[visited[0]] = null;
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while(toCheck.length > 0) {
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const positionString = toCheck.shift();
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const positionObj = { x: parseInt(positionString.split(":")[0]), y: parseInt(positionString.split(":")[1])};
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if(positionObj.x - 1 >= 0 && (
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(map[positionObj.y][positionObj.x - 1].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) === 1 ||
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(map[positionObj.y][positionObj.x - 1].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) < 1
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)) {
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const str = `${positionObj.x - 1}:${positionObj.y}`;
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if(!visited.includes(str)) {
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toCheck.push(str);
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visited.push(str);
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whereFrom[str] = positionString;
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}
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}
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if(positionObj.x + 1 < dimensions.width && (
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(map[positionObj.y][positionObj.x + 1].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) === 1 ||
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(map[positionObj.y][positionObj.x + 1].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) < 1
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)) {
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const str = `${positionObj.x + 1}:${positionObj.y}`;
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if(!visited.includes(str)) {
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toCheck.push(str);
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visited.push(str);
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whereFrom[str] = positionString;
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}
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}
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if(positionObj.y - 1 >= 0 && (
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(map[positionObj.y - 1][positionObj.x].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) === 1 ||
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(map[positionObj.y - 1][positionObj.x].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) < 1
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)) {
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const str = `${positionObj.x}:${positionObj.y - 1}`;
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if(!visited.includes(str)) {
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toCheck.push(str);
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visited.push(str);
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whereFrom[str] = positionString;
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}
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}
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if(positionObj.y + 1 < dimensions.height && (
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(map[positionObj.y + 1][positionObj.x].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) === 1 ||
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(map[positionObj.y + 1][positionObj.x].charCodeAt(0) - map[positionObj.y][positionObj.x].charCodeAt(0)) < 1
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)) {
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const str = `${positionObj.x}:${positionObj.y + 1}`;
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if(!visited.includes(str)) {
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toCheck.push(str);
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visited.push(str);
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whereFrom[str] = positionString;
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}
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}
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if(positionObj.x === endingPos.x && positionObj.y === endingPos.y) {
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let count = 0;
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let currentPoint = positionString;
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while(1) {
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currentPoint = whereFrom[currentPoint]
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if(currentPoint === null) return count;
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count++;
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}
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}
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}
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}
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let index = 0;
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const heightMap = [];
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const startingPoints = [];
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const end = { x: 0, y: 0 };
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input.split('\n').forEach(line => {
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heightMap[index] = [...line.split("")];
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if(line.includes("a")) startingPoints.push({ x: heightMap[index].indexOf("a"), y: index });
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if(line.includes("S")) {
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const startingIndex = heightMap[index].indexOf("S")
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heightMap[index][startingIndex] = "a";
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startingPoints.push({ x: startingIndex, y: index });
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}
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if(line.includes("E")) {
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const endingIndex = heightMap[index].indexOf("E")
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heightMap[index][endingIndex] = "z";
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end.x = endingIndex;
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end.y = index;
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}
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index++;
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});
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const results = []
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startingPoints.forEach(start => {
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results.push(BFS(heightMap, [`${start.x}:${start.y}`], [`${start.x}:${start.y}`], end, { height: index, width: heightMap[0].length }))
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});
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console.log(results.sort((a, b) => a - b)[0]) |