add: validating-a-maze-path

Author: supercodestart

README.md

@@ -5,3 +5,4 @@
 - [Finding the maximum depth of a binary tree](finding-the-maximum-depth-of-a-binary-tree)
 - [Getting the distinct transactions](getting-the-distinct-transactions)
 - [Replacing with the cipher letters](replacing-with-the-cipher-letters)
+- [Validating a maze path](validating-a-maze-path)

validating-a-maze-path/README.md

@@ -0,0 +1,43 @@
+# Validating a maze path
+
+Validate the provided maze path is correct.
+
+e.g.:
+
+Maze matrix
+
+```console
+[
+  [1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+  [1, 0, 1, 0, 1, 0, 0, 0, 1, 1],
+  [1, 0, 1, 0, 1, 0, 1, 0, 0, 1],
+  [1, 0, 1, 0, 1, 1, 1, 1, 0, 1],
+  [1, 0, 1, 0, 0, 0, 0, 1, 0, 1],
+  [1, 0, 1, 0, 1, 0, 1, 1, 0, 1],
+  [1, 0, 0, 0, 1, 0, 0, 1, 0, 1],
+  [1, 0, 1, 1, 1, 1, 0, 0, 0, 1],
+  [1, 0, 1, 0, 0, 0, 0, 1, 0, 1],
+  [1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+]
+```
+
+Input
+
+```console
+startRow = 1
+startCol = 1
+destRow = 2
+destCol = 5
+```
+
+Output
+
+```console
+true
+```
+
+## Execute
+
+```bash
+node solution.js
+```

validating-a-maze-path/solution.js

@@ -0,0 +1,94 @@
+const solution = (
+  maze,
+  startRow,
+  startCol,
+  destRow,
+  destCol,
+) => {
+  if (
+    maze[startRow][startCol] == 1 ||
+    maze[destRow][destCol] == 1
+  ) {
+    return false;
+  }
+
+  let slots = [{ row: startRow, col: startCol }];
+  let tried = [];
+  let path = false;
+
+  const steps = [
+    { row: -1, col: 0 },
+    { row: +1, col: 0 },
+    { row: 0, col: -1 },
+    { row: 0, col: +1 },
+  ];
+
+  while (slots.length > 0 && !path) {
+    [...slots].forEach((slot) => {
+      tried.push(slot);
+
+      slots = slots.filter(
+        (s) => !(s.row == slot.row && s.col == slot.col),
+      );
+
+      for (const step of steps) {
+        if (
+          slot.row + step.row == destRow &&
+          slot.col + step.col == destCol
+        ) {
+          path = true;
+          return;
+        }
+      }
+
+      for (const step of steps) {
+        const next = {
+          row: slot.row + step.row,
+          col: slot.col + step.col,
+        };
+
+        if (
+          next.row < 0 ||
+          next.row >= maze.length ||
+          next.col < 0 ||
+          next.col >= maze[0].length
+        ) {
+          continue;
+        }
+
+        if (
+          tried.find(
+            (t) => t.row == next.row && t.col == next.col,
+          )
+        ) {
+          continue;
+        }
+
+        if (maze[next.row][next.col] == 1) {
+          continue;
+        }
+
+        slots.push(next);
+      }
+    });
+  }
+
+  return path;
+};
+
+(() => {
+  const maze = [
+    [1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+    [1, 0, 1, 0, 1, 0, 0, 0, 1, 1],
+    [1, 0, 1, 0, 1, 0, 1, 0, 0, 1],
+    [1, 0, 1, 0, 1, 1, 1, 1, 0, 1],
+    [1, 0, 1, 0, 0, 0, 0, 1, 0, 1],
+    [1, 0, 1, 0, 1, 0, 1, 1, 0, 1],
+    [1, 0, 0, 0, 1, 0, 0, 1, 0, 1],
+    [1, 0, 1, 1, 1, 1, 0, 0, 0, 1],
+    [1, 0, 1, 0, 0, 0, 0, 1, 0, 1],
+    [1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
+  ];
+
+  console.log(solution(maze, 1, 1, 2, 5));
+})();