add DFS solution(low efficiency)

Author: zouwx2cs

solution/0064.Minimum Path Sum/Solution2.cpp

@@ -0,0 +1,25 @@
+class Solution {
+private:
+    void dfs(vector<vector<int>> &g, 
+             vector<vector<int>> &dis, 
+             int i, int j, int d)
+    {
+        if (i >= dis.size() || j >= dis[0].size())
+            return ;
+        
+        d += g[i][j] ;
+        if (dis[i][j] >= 0 && d >= dis[i][j])
+            return ;
+        
+        dis[i][j] = d ;
+        
+        dfs(g, dis, i+1, j, d) ;
+        dfs(g, dis, i, j+1, d) ;
+    }
+public:
+    int minPathSum(vector<vector<int>>& grid) {
+        vector<vector<int>> dis(grid.size(), vector<int>(grid.at(0).size(), -1)) ;
+        dfs(grid, dis, 0, 0, 0) ;
+        return dis.back().back() ;
+    }
+};