2328. Number of Increasing Paths in a Grid

class Solution {
    int mod = 1_000_000_007;
    int m=0,n=0;
    int[][] dp = null;
    int[][] dir = new int[][]{{1,0},{0,1},{-1,0},{0,-1}};
    public int countPaths(int[][] grid) {
        m = grid.length;
        n=grid[0].length;
        dp = new int[m][n];
        int res =0;
        for(int i=0;i<m;i++){
            for(int j=0;j<n;j++){
                res = (res + dfs(grid,i,j,-1))%mod;
            }
        }
        return res;
    }

    private int dfs(int[][] grid,int si,int sj,int prev){
        if(si<0 || sj<0 || si>=m || sj>=n || grid[si][sj]<=prev){
            return 0;
        }
        if(dp[si][sj]>0) return dp[si][sj];
        int path  = 1;
        for(int[] d:dir){
            path += dfs(grid,si+d[0],sj+d[1],grid[si][sj]);
        }
        
        path%=mod;
        dp[si][sj] = path;
        return path;
    }
}