1559. Detect Cycles in 2D Grid.txt

https://leetcode.com/problems/detect-cycles-in-2d-grid/

class Solution {
public:
    int dirsx[4] = {0, 0, -1, 1}, dirsy[4] = {-1, 1, 0, 0};
    bool hasCycle(vector<vector<char>>& grid, vector<vector<int>>& visited, int i, int j, char target, pair<int, int> prev) {
        if (i < 0 || j < 0 || i >= grid.size() || j >= grid[0].size() || visited[i][j] == 2 || grid[i][j] != target)
            return false;
        if (visited[i][j] == 1)
            return true;
        visited[i][j] = 1;
        for (int d = 0; d < 4; ++d) {
            int tx = i + dirsx[d], ty = j + dirsy[d];
            if ((tx != prev.first || ty != prev.second) && hasCycle(grid, visited, tx, ty, target, {i, j}))
                return true;
        }
        visited[i][j] = 2;
        return false;
    }
    
    bool containsCycle(vector<vector<char>>& grid) {
        vector<vector<int>> visited(grid.size(), vector<int>(grid[0].size()));
        for (int i = 0; i < grid.size(); ++i) {
            for (int j = 0; j < grid[0].size(); ++j) {
                if (!visited[i][j] && hasCycle(grid, visited, i, j, grid[i][j], {-1, -1}))
                    return true;
            }
        }
        return false;
    }
};