1036. Escape a Large Maze
Description
There is a 1 million by 1 million grid on an XY-plane, and the coordinates of each grid square are (x, y)
.
We start at the source = [sx, sy]
square and want to reach the target = [tx, ty]
square. There is also an array of blocked
squares, where each blocked[i] = [xi, yi]
represents a blocked square with coordinates (xi, yi)
.
Each move, we can walk one square north, east, south, or west if the square is not in the array of blocked
squares. We are also not allowed to walk outside of the grid.
Return true
if and only if it is possible to reach the target
square from the source
square through a sequence of valid moves.
Example 1:
Input: blocked = [[0,1],[1,0]], source = [0,0], target = [0,2] Output: false Explanation: The target square is inaccessible starting from the source square because we cannot move. We cannot move north or east because those squares are blocked. We cannot move south or west because we cannot go outside of the grid.
Example 2:
Input: blocked = [], source = [0,0], target = [999999,999999] Output: true Explanation: Because there are no blocked cells, it is possible to reach the target square.
Constraints:
0 <= blocked.length <= 200
blocked[i].length == 2
0 <= xi, yi < 106
source.length == target.length == 2
0 <= sx, sy, tx, ty < 106
source != target
- It is guaranteed that
source
andtarget
are not blocked.
Solutions
Solution 1
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