Check if There is a Valid Path in a Grid LeetCode solution in C++

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class Solution {
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  int n, m;
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  bool vis[305][305];
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  vector<vector<int>> g;
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 public:
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  bool hasValidPath(vector<vector<int>> &grid) {
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    n = grid.size();
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    m = grid[0].size();
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    g = grid;
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    memset(vis, false, sizeof(vis));
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    dfs(0, 0);
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    return vis[n - 1][m - 1];
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  }
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  void dfs(int ux, int uy) {
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    vis[ux][uy] = true;
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    int vx, vy;
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    if (g[ux][uy] == 1 || g[ux][uy] == 4 || g[ux][uy] == 6) {
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      vx = ux, vy = uy + 1;
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      if (valid(vx, vy) && L_enter(vx, vy)) dfs(vx, vy);
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    }
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    if (g[ux][uy] == 1 || g[ux][uy] == 3 || g[ux][uy] == 5) {
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      vx = ux, vy = uy - 1;
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      if (valid(vx, vy) && R_enter(vx, vy)) dfs(vx, vy);
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    }
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    if (g[ux][uy] == 2 || g[ux][uy] == 3 || g[ux][uy] == 4) {
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      vx = ux + 1, vy = uy;
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      if (valid(vx, vy) && D_enter(vx, vy)) dfs(vx, vy);
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    }
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    if (g[ux][uy] == 2 || g[ux][uy] == 5 || g[ux][uy] == 6) {
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      vx = ux - 1, vy = uy;
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      if (valid(vx, vy) && U_enter(vx, vy)) dfs(vx, vy);
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    }
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  }
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  bool valid(int x, int y) {
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    if (x >= 0 && y >= 0 && x < n && y < m && !vis[x][y]) return true;
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    return false;
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  }
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  bool L_enter(int x, int y) {
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    if (g[x][y] % 2) return true;
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    return false;
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  }
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  bool R_enter(int x, int y) {
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    if (g[x][y] == 1 || g[x][y] == 4 || g[x][y] == 6) return true;
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    return false;
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  }
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  bool D_enter(int x, int y) {
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    if (g[x][y] == 2 || g[x][y] == 5 || g[x][y] == 6) return true;
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    return false;
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  }
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  bool U_enter(int x, int y) {
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    if (g[x][y] == 2 || g[x][y] == 3 || g[x][y] == 4) return true;
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    return false;
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  }
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};