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package Ic2ExpReactorPlanner;
import java.math.BigInteger;
import java.util.Base64;
/**
* Stores numbers of varying size inside a BigInteger, expecting each to have
* a defined limit (which need not be an exact power of 2). Numbers are to be
* extracted in reverse order they were stored, and special values can be used
* to make certain values optional for inclusion (the calling class is
* responsible for handling this logic, though).
* @author Brian McCloud
*/
public class BigintStorage {
private BigInteger storedValue = BigInteger.ZERO;
/**
* Stores the specified value. Requires that 0 <= value <= max.
* @param value the value to store.
* @param max the expected maximum for the value.
*/
public void store(int value, int max) {
if (value < 0 || value > max) {
throw new IllegalArgumentException();
}
storedValue = storedValue.multiply(BigInteger.valueOf(max + 1)).add(BigInteger.valueOf(value));
}
/**
* Extracts a value based on the specified maximum.
* @param max the expected maximum for the value.
* @return the extracted value.
*/
public int extract(int max) {
BigInteger[] values = storedValue.divideAndRemainder(BigInteger.valueOf(max + 1));
storedValue = values[0];
return values[1].intValue();
}
/**
* Takes input of a Base64 string, and converts it to a BigintStorage.
* @param code the Base64-encoded string (presumed to be from @outputBase64)
* @return the converted storage object.
*/
public static BigintStorage inputBase64(String code) {
BigintStorage result = new BigintStorage();
byte[] temp = Base64.getDecoder().decode(code);
result.storedValue = new BigInteger(temp);
return result;
}
/**
* Outputs the current value of this BigintStorage as a Base64-encoded string.
* @return the Base64-encoded string.
*/
public String outputBase64() {
byte[] temp = storedValue.toByteArray();
return Base64.getEncoder().encodeToString(temp);
}
}
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