329 Longest Increasing Path in a Matrix

Given an integer matrix, find the length of the longest increasing path.

From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed).

Example 1:

Input: nums = 
[
  [9,9,4],
  [6,6,8],
  [2,1,1]
] 
Output: 4 
Explanation: The longest increasing path is [1, 2, 6, 9].


public int longestIncreasingPath(int[][] matrix) {
        if(matrix.length==0)return 0;
        int max = 0;
        for(int i=0;i<matrix.length;i++){
            for(int j=0;j<matrix[0].length;j++){
                    max = Math.max(dfs(matrix,i,j,Integer.MIN_VALUE),max);
                }
            }
        
       return max;

        }

    
    int dfs(int[][] matrix,int i,int j,int pre){
        if(i<0 || j<0 || i>matrix.length-1 || j>matrix[0].length-1)return 0;
        else if(pre>=matrix[i][j])return 0;
     
        
         
        int path1 =  dfs(matrix,i-1,j,matrix[i][j]); 
        int path2 =  dfs(matrix,i+1,j,matrix[i][j]); 
        int path3 =  dfs(matrix,i,j-1,matrix[i][j]); 
        int path4 =  dfs(matrix,i,j+1,matrix[i][j]); 
         

        int max1 = Math.max(path1,path2);
        int max2 = Math.max(path3,path4);
        
        int count = 1+Math.max(max1,max2);
          
        
        return count; 
    }