class Solution { public boolean isAdditiveNumber(String num) { int len = num.length(); if(len<3) return false; return dfs(new ArrayList<>(), num, 0); } private boolean dfs(List<Long> curResult, String s, int start){ if(curResult.size() >=3 && start==s.length()){ return true; } boolean flag = false; for(int i=1; i<=s.length()-2; i++){ if(start+i >s.length()) break; int size = curResult.size(); String substr = s.substring(start,start+i); if(substr.length()>1 && substr.charAt(0) == '0') continue; long subnum = Long.valueOf(substr); if(size>=2) if(curResult.get(size-1) + curResult.get(size-2) != subnum) continue; curResult.add(subnum); start += i; flag = flag || dfs(curResult,s,start); if(flag) return true; curResult.remove(curResult.size()-1); start -=i; } return flag; } } class Solution { public List<Integer> splitIntoFibonacci(String S) { List<Integer> result = new ArrayList<>(); if(S.length()<3 ) return result; dfs(result, S,0); return result; } private boolean dfs(List<Integer> curResult, String s, int start){ if(curResult.size() >=3 && start==s.length()){ return true; } boolean flag = false; for(int i=1; i<=(s.length()-2 <10? s.length()-2:10); i++){ if(start+i >s.length()) break; int size = curResult.size(); String substr = s.substring(start,start+i); if(substr.length()>1 && substr.charAt(0) == '0') continue; long subnum = Long.valueOf(substr); if(subnum > Integer.MAX_VALUE) continue; if(size>=2) if(curResult.get(size-1) + curResult.get(size-2) != subnum) continue; curResult.add((int)subnum); start += i; flag = flag || dfs(curResult,s,start); if(flag) return true; curResult.remove(curResult.size()-1); start -=i; } return flag; } } 