Time: 4 ms (95.02%), Space: 44.2 MB (95.43%) - LeetHub

Author: Sangram03

0945-snakes-and-ladders/0945-snakes-and-ladders.java

@@ -0,0 +1,27 @@
+class Solution {
+    public int snakesAndLadders(int[][] board) {
+        int n = board.length;
+        int[] min_rolls = new int[n * n + 1];
+        Arrays.fill(min_rolls, -1);
+        Queue<Integer> q = new LinkedList<>();
+        min_rolls[1] = 0;
+        q.offer(1);
+
+        while (!q.isEmpty()) {
+            int x = q.poll();
+            for (int i = 1; i <= 6 && x + i <= n * n; i++) {
+                int t = x + i;
+                int row = (t - 1) / n;
+                int col = (t - 1) % n;
+                int v = board[n - 1 - row][(row % 2 == 1) ? (n - 1 - col) : col];
+                int y = (v > 0 ? v : t);
+                if (y == n * n) return min_rolls[x] + 1;
+                if (min_rolls[y] == -1) {
+                    min_rolls[y] = min_rolls[x] + 1;
+                    q.offer(y);
+                }
+            }
+        }
+        return -1;
+    }
+}