一、题目内容

二、题解

解法1：

思路

代码

public class Solution {
    private int maxans = 0;
    public int solve (int[][] matrix) {
        // write code here
        if (matrix == null || matrix.length == 0 || matrix.length == 0) {
            return 0;
        }
        int rows = matrix.length;
        int cols = matrix[0].length;
        int[][] visited = new int[rows][cols];
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                recur(matrix, visited, i, j, -1, 0);
            }
        }
        return maxans;
    }
    private void recur(int[][] matrix, int[][] visited, int i, int j, int cur, int step){
        if (i < 0 || i > matrix.length - 1 || j < 0 || j > matrix[0].length - 1 ||
           visited[i][j] == 1 || cur >= matrix[i][j]) {
            return;
        }
        step++;
        maxans = Math.max(maxans,step);
        visited[i][j] = 1;
        recur(matrix,visited,i-1,j,matrix[i][j],step);
        recur(matrix,visited,i,j-1,matrix[i][j],step);
        recur(matrix,visited,i+1,j,matrix[i][j],step);
        recur(matrix,visited,i,j+1,matrix[i][j],step);
        visited[i][j] = 0;
    }
}