leetcode 字符串分割对称

public class Solution {
    public List<List<String>> partition(String s) {
        int len=s.length();
           boolean dp[][]=new boolean[len][len];
           get(dp,s);
           ArrayList<ArrayList<String>> res=new ArrayList<ArrayList<String>>();
           ArrayList<String> temp=new ArrayList<String>();
           dfs(res,temp,0,dp,s);
           return (List)res;
           
        
    }
    public void get(boolean dp[][],String s)
    {
        char c[]=s.toCharArray();
        int len=s.length();
      //single character is duichen
      for(int i=0;i<len-1;i++)
      {
          dp[i][i]=true;
          if(c[i]==c[i+1]) dp[i][i+1]=true;
          
      }
      dp[len-1][len-1]=true;
        
        for(int l=2;l<len;l++)
        {
            for(int k=0;k<len-l;k++)
            {
                dp[k][k+l]=dp[k+1][k+l-1]&&(c[k]==c[k+l]);
            }
    
        }
        
        
        
    }
public void dfs(ArrayList<ArrayList<String>> res,ArrayList<String> temp,int l,boolean dp[][],String s)
    {
        if(l==dp.length)
        {
           res.add(new ArrayList(temp));   
        }
        else
        {
            for(int j=0;j<dp.length;j++)
            {
                if(dp[l][j])
                {
                    ArrayList<String> t=new ArrayList<String>(temp);
                    t.add(s.substring(l,j+1));
                    dfs(res,t,j+1,dp,s);
                    
                }
                    
                
            }
                
             }
    }
    
    
    
    
}