function distanceGrid(maze, startPos) {
let [sRow, sCol] = [0, 0];
if (startPos !== undefined) {
[sRow, sCol] = startPos;
} else if (maze.srt) {
[sRow, sCol] = [maze.getStart().row, maze.getStart().col];
}
const distances = maze.grid.map((row) => Array(row.length).fill(Infinity));
const startRow = maze.getStart(sRow, sCol).row;
const startCol = maze.getStart(sRow, sCol).col;
// Breadth first search from the startng position
let queue = [maze.grid[startRow][startCol]];
distances[startRow][startCol] = 0;
while (queue.length > 0) {
const c = queue.shift();
for (let linked of c.links) {
if (distances[linked.row]?.[linked.col] === Infinity) {
distances[linked.row][linked.col] = distances[c.row][c.col] + 1;
queue.push(linked);
}
}
}
return distances;
}
function composeLongest(m, opt) {
const defaults = { r: new Renderer(300, 300), cShortest: composeShortest };
opt = Object.assign({}, opt, defaults);
const furthest = (ds) => {
let [maxD, maxPos] = [ds[0][0], [0, 0]];
for (let row = 0; row < m.nRows; row++) {
for (let col = 0; col < m.grid[row].length; col++) {
if (ds[row][col] > maxD) {
maxD = ds[row][col];
maxPos = [row, col];
}
}
}
return maxPos;
};
// Find the longest distance from some arbitrary start point:
const cellA = furthest(distanceGrid(m, [0, 0]));
const cellB = furthest(distanceGrid(m, cellA));
return opt.cShortest(m, { ...opt, start: cellA, end: cellB });
}
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
