Java || BigInteger || Easy to UnderStand
\nimport java.math.BigInteger;\nclass Solution {\n    public List<Integer> addToArrayForm(int[] num, int k) {\n        String s="";\n        for(int i:num){\n  
```\nimport java.math.BigInteger;\nclass Solution {\n    public List<Integer> addToArrayForm(int[] num, int k) {\n        String s="";\n        for(int i:num){\n            s+=i;\n        }\n        String kk=k+"";\n        List<Integer> al=new ArrayList<>();\n        BigInteger a=new BigInteger(s);\n        BigInteger b=new BigInteger(kk);\n        BigInteger c=a.add(b);\n        String str=c.toString();\n        for(char ch:str.toCharArray()){\n            al.add(ch-\'0\');\n        }\n        return al;\n    }\n}\n```
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