1 files changed, 104 insertions, 0 deletions
diff --git a/maize-maze/js/maze.js b/maize-maze/js/maze.js
new file mode 100644
index 0000000..8bede6b
--- /dev/null
+++ b/maize-maze/js/maze.js
@@ -0,0 +1,104 @@
+function get_neighbors(maze, x, y) {
+  let neighbor_indices = [];
+  if (!maze[y][x].left && x > 0) {
+    neighbor_indices.push([x-1,y]);
+  }
+  if (!maze[y][x].right && x < maze[0].length-1) {
+    neighbor_indices.push([x+1,y]);
+  }
+  if (!maze[y][x].top && y > 0) {
+    neighbor_indices.push([x,y-1]);
+  }
+  if (!maze[y][x].bottom && y < maze.length-1) {
+    neighbor_indices.push([x,y+1]);
+  }
+  return neighbor_indices;
+}
+
+function new_cell() {
+  return {
+    left: false,
+    right: false, 
+    top: false, 
+    bottom: false
+  }
+}
+
+function generate_maze(n) {
+  let grid = new Array(n).fill().map((x) => (new Array(n).fill().map(new_cell)));
+
+  let point_sets = [];
+  for (let i = 0; i < n; i++) {
+    for (let j = 0; j < n; j++) {
+      point_sets.push(new JSONSet([j,i]))
+    }
+  }
+
+  let edges = [];
+  for (let i = 0; i < n; i++) {
+    for (let j = 0; j < n; j++) {
+      if (i !== n-1) {
+        edges.push([[i,j],[i+1,j]])
+      }
+      if (j !== n-1) {
+        edges.push([[i,j],[i,j+1]])
+      }
+    }
+  }
+  shuffle_array(edges);
+
+  let maze_edges = edges.map((x) => x);
+
+  while (edges.length) {
+    let edge = edges.pop();
+
+    let set_inds = edge.map((i) => point_sets.findIndex((x) => x.apply_set_function('has', i)));
+    if (set_inds[0] == -1 || set_inds[1] == -1) {
+      throw new Error("Could not find correct index");
+    }
+    if (set_inds[0] == set_inds[1]) {
+      continue;
+    }
+
+    // Perform the union of the sets
+    for (let i of point_sets[set_inds[1]].items) {
+      point_sets[set_inds[0]].items.add(i);
+    }
+
+    point_sets.splice(set_inds[1], 1);
+    maze_edges = maze_edges.filter((x) => x !== edge);
+  }
+  maze_edges.forEach((edge) => {
+    let direction = sub(edge[0], edge[1]);
+    if (direction[0] == -1) {
+      grid[edge[0][1]][edge[0][0]].right = grid[edge[1][1]][edge[1][0]].left = true;
+    }
+    else if (direction[1] == -1) {
+      grid[edge[0][1]][edge[0][0]].bottom = grid[edge[1][1]][edge[1][0]].top = true;
+    }
+  })
+  return grid;
+}
+
+function solve_maze(maze, x, y, end_x, end_y) {
+  let path = new JSONHash();
+  let visited = new JSONSet();
+  let queue = [[x,y]];
+  while (queue.length) {
+    let cell = queue.shift();
+    visited.apply_set_function('add', cell);
+    if (cell[0] == end_x && cell[1] == end_y) {
+      let sol_path = [[end_x, end_y]];
+      while (sol_path[0][0] != x || sol_path[0][1] != y) {
+        sol_path.unshift(path.get_value(sol_path[0]));
+      }
+      return sol_path;
+    }
+    for (let i of get_neighbors(maze, cell[0], cell[1])) {
+      if (!visited.apply_set_function('has', i)) {
+        queue.push(i);
+        path.set_value(i, cell);
+      }
+    }
+  }
+}