# ---
# title: 1036. Escape a Large Maze
# id: problem1036
# author: Tian Jun
# date: 2020-10-31
# difficulty: Hard
# categories: Breadth-first Search
# link: <https://leetcode.com/problems/escape-a-large-maze/description/>
# hidden: true
# ---
# 
# In a 1 million by 1 million grid, the coordinates of each grid square are `(x,
# y)`.
# 
# We start at the `source` square and want to reach the `target` square.  Each
# move, we can walk to a 4-directionally adjacent square in the grid that isn't
# in the given list of `blocked` squares.
# 
# Return `true` if and only if it is possible to reach the target square through
# a sequence of 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 can't walk outside the grid.
#     
# 
# **Example 2:**
# 
#     
#     
#     Input: blocked = [], source = [0,0], target = [999999,999999]
#     Output: true
#     Explanation: Because there are no blocked cells, it's possible to reach the target square.
#     
# 
# 
# 
# **Constraints:**
# 
#   * `0 <= blocked.length <= 200`
#   * `blocked[i].length == 2`
#   * `0 <= blocked[i][j] < 10^6`
#   * `source.length == target.length == 2`
#   * `0 <= source[i][j], target[i][j] < 10^6`
#   * `source != target`
# 
# 
## @lc code=start
using LeetCode

## add your code here:
## @lc code=end
