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 });
}
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.