Tear my Java solution to pieces and tell me how it could be improved :D

void decode(String S, Node root)
{
    StringBuilder sb = new StringBuilder();
    Node c = root;
    for (int i = 0; i < S.length(); i++) {
        c = S.charAt(i) == '1' ? c.right : c.left;
        if (c.left == null && c.right == null) {
            sb.append(c.data);
            c = root;
        }
    }
    System.out.print(sb);
}

I'm confused, when I run my code it says:

Nice try, but you did not pass this test case.

Input (stdin)

ABACA

But that looks like output, not input. If that is actually an input the problem description is very unclear.

void decode_huff(node * root,string s) { node * ptr; int n;

ptr = root;
for(n=0;s[n];n++)
{
    ptr = (s[n] == '0') ? ptr->left : ptr->right;
    if(ptr->data)
    {
        cout << ptr->data;
        ptr = root;
    }
}

}

one line solution trick just write in def_decodehuff: print(ip)

thanks me later

Input & Output test cases are same Strings. Can you please check it? Ex: Test case 4, Input and Output are "HackerRank". (Or only for me?)