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Recursive Tracing

Language/Type: Java mod recursion recursive tracing
Author: Stuart Reges (on 2014/02/13)

Consider the following method: 

    public int mystery(int n) {
        if (n < 0) {
            return -mystery(-n);
        } else if (n < 10) {
            return (n + 1) % 10;
        } else {
            return 10 * mystery(n / 10) + (n + 1) % 10;
    }
    }

For each call below, indicate what value is returned:

mystery(7)
mystery(42)
mystery(385)
mystery(-790)
mystery(89294)

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