leetcode：1219. 黄金矿工（dfs）

链接：https://leetcode-cn.com/problems/path-with-maximum-gold/
dfs即可，注意dfs时不能重复进入一个矿洞。
C++代码：

class Solution {
public:
    int getMaximumGold(vector<vector<int>>& grid) {
        int res = 0;
        for(int i = 0;i<grid.size();i++)
        {
            for(int j = 0;j<grid[0].size();j++)
            {
                if(grid[i][j]!=0)
                {
                       res = max(res,dfs(grid,i,j,0));
                }
            }
        }
        return res;
    }
    int dfs(vector<vector<int>>& grid, int i,int j,int sum)
    {
        if(i<0||i>=grid.size()||j<0||j>=grid[0].size()||grid[i][j]==0)
            return sum;
        int temp = grid[i][j];
        grid[i][j] = 0;
        int temp1 = max(dfs(grid,i-1,j,sum+temp),dfs(grid,i+1,j,sum+temp));
        int temp2 = max(dfs(grid,i,j-1,sum+temp),dfs(grid,i,j+1,sum+temp));
        grid[i][j] = temp;
        return max(temp1,temp2);
    }
};