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Using a stack integer of length n can be added here. Same can be done for subtraction.

Stack st1 = new Stack();
Stack st2 = new Stack();
//Adding number 129 + 138 split it and push to stack.
st1.push(1);
st1.push(2);
st1.push(9);

st2.push(1);
st2.push(3);
st2.push(8);
StringBuffer res= new StringBuffer();
int carry = 0;
for(int i =0 ; i < 3;i++){
    int a = (int) st1.pop();
    int b = (int) st2.pop();
    int temp = a + b + carry;
    if(temp > 9){
        carry = 1;
        temp = temp - 10;
    }
    else{
        carry = 0;
    }
    res = res.append(temp);
}
System.out.println(res.reverse());

Courtesy - https://sites.google.com/site/arjunwebworld/Home/programming/programmatic-questions

You can use linkedlist for that

yes we can use linked list to implement this :)

Use Vector or ArrayList. Easy to traverse

we can use a int array, check the BigInteger implementation in java.