题解 | #矩阵中的路径#

题目理解清楚：机器人从（0，0）出发，问可以走到多少格子，不是求一条路径的最大值而是所以可以走的路径中不重复的格子数

public class Solution {
    
    public int ans = 0;
    public int threshold = 0;
    public int rows = 0,cols = 0;
    public int[][] visit = new int[101][101];
    
    public void dfs(int i,int j,int count){
        if(i<0||j<0||i>=rows||j>=cols||visit[i][j] == 1)return;
        
        int temp = 0;
        String s = String.valueOf(i)+String.valueOf(j);
        for(int k = 0; k < s.length(); k++)temp+=s.charAt(k)-'0';
        if(temp >threshold)return;
        ans++;
         
        visit[i][j] = 1;
        dfs(i+1,j,count+1);
        dfs(i,j+1,count+1);
        dfs(i-1,j,count+1);
        dfs(i,j-1,count+1);
    } 
    public int movingCount(int threshold, int rows, int cols) {
        this.threshold = threshold;
        this.rows = rows;
        this.cols = cols;
        dfs(0,0,1);
        return ans;
    }
}