Main.java:13: error: cannot find symbol
    	if(list.length == k){
    	       ^
  symbol:   variable length
  location: variable list of type List<Integer>
Main.java:17: error: cannot find symbol
      if(list.length +n-cur<k){
             ^
  symbol:   variable length
  location: variable list of type List<Integer>
Main.java:22: error: cannot find symbol
      list.remove(list.length - 1);
                      ^
  symbol:   variable length
  location: variable list of type List<Integer>
Main.java:27: error: incompatible types: List<List<Integer>> cannot be converted to List<List<String>>
      return ans;
             ^
4 errors