题解 | #矩阵最长递增路径#

import java.util.*;


public class Solution {
    private int maxPath=0;
    public int solve (int[][] matrix) {
        // write code here
        int row=matrix.length;
        if(row==0){
            return 0;
        }
        int col=matrix[0].length;
        for(int i=0;i<row;i++){
            for(int j=0;j<col;j++){
                dfs(matrix,i,j,row,col,1);
            }
        }
        return maxPath;
    }

    public void dfs(int[][]matrix, int i,int j,int row,int col,int k){
        if(i<0||j<0||i>=row||j>=col){
            return;
        }

        if(i>0){
            if(matrix[i-1][j]>matrix[i][j]){
             dfs(matrix,i-1,j,row,col,k+1);
            }
        }
        if(j>0){
             if(matrix[i][j-1]>matrix[i][j]){
                
             dfs(matrix,i,j-1,row,col,k+1);
            }
        }
        if(i<row-1){
              if(matrix[i+1][j]>matrix[i][j]){
             dfs(matrix,i+1,j,row,col,k+1);
            }
        }
        if(j<col-1){
              if(matrix[i][j+1]>matrix[i][j]){
             dfs(matrix,i,j+1,row,col,k+1);
            }
        }
        maxPath=Math.max(maxPath,k);
    }
}