{ "data": { "question": { "questionId": "1663", "questionFrontendId": "1559", "boundTopicId": null, "title": "Detect Cycles in 2D Grid", "titleSlug": "detect-cycles-in-2d-grid", "content": "
Given a 2D array of characters grid
of size m x n
, you need to find if there exists any cycle consisting of the same value in grid
.
A cycle is a path of length 4 or more in the grid that starts and ends at the same cell. From a given cell, you can move to one of the cells adjacent to it - in one of the four directions (up, down, left, or right), if it has the same value of the current cell.
\n\nAlso, you cannot move to the cell that you visited in your last move. For example, the cycle (1, 1) -> (1, 2) -> (1, 1)
is invalid because from (1, 2)
we visited (1, 1)
which was the last visited cell.
Return true
if any cycle of the same value exists in grid
, otherwise, return false
.
\n
Example 1:
\n\n\n\n
\nInput: grid = [["a","a","a","a"],["a","b","b","a"],["a","b","b","a"],["a","a","a","a"]]\nOutput: true\nExplanation: There are two valid cycles shown in different colors in the image below:\n\n\n\n
Example 2:
\n\n\n\n
\nInput: grid = [["c","c","c","a"],["c","d","c","c"],["c","c","e","c"],["f","c","c","c"]]\nOutput: true\nExplanation: There is only one valid cycle highlighted in the image below:\n\n\n\n
Example 3:
\n\n\n\n
\nInput: grid = [["a","b","b"],["b","z","b"],["b","b","a"]]\nOutput: false\n\n\n
\n
Constraints:
\n\nm == grid.length
n == grid[i].length
1 <= m, n <= 500
grid
consists only of lowercase English letters.Compiled with clang 11
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Your code is compiled with level two optimization (-O2
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Most standard library headers are already included automatically for your convenience.
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