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Fix number of digit computation for decompose in IntegerRing.java. #75

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Merged
this-kramer merged 3 commits into from
Apr 5, 2021
Merged

Fix number of digit computation for decompose in IntegerRing.java. #75

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e0d3cc2
Fix number of digit computation for decompose in IntegerRing.java.
this-kramer Apr 5, 2021
d53def0
Fix docstring formatting
this-kramer Apr 5, 2021
c7e001f
Change comment
this-kramer Apr 5, 2021
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12 changes: 6 additions & 6 deletions src/main/java/org/cryptimeleon/math/structures/rings/integers/IntegerRing.java
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Original file line number Diff line number Diff line change
Expand Up @@ -97,14 +97,14 @@ public boolean isCommutative() {
* For example, for base = 2, this does bit decomposition.
*
* @return an array {@code A} containing values {@code A[i] < base} such that
* \(\sum_i{ \text{A}[i] \cdot \text{base}^i} = \text{number}\)
* \(\sum_i{ \text{A}[i] \cdot \text{base}^i} = \text{number}\)
*/
public static BigInteger[] decomposeIntoDigits(BigInteger number, BigInteger base) {
int power = 0;
BigInteger numberPowered = BigInteger.ONE;
// as soon as number is smaller than number^power, it can be decomposed into power digits.
while (numberPowered.compareTo(number) < 0) {
numberPowered = numberPowered.multiply(number);
BigInteger basePower = BigInteger.ONE;
// as soon as number is smaller than base^power, it can be decomposed into power digits.
while (basePower.compareTo(number) < 0) {
basePower = basePower.multiply(base);
power++;
}
return decomposeIntoDigits(number, base, power);
Expand All @@ -116,7 +116,7 @@ public static BigInteger[] decomposeIntoDigits(BigInteger number, BigInteger bas
* For example, for base = 2, this does bit decomposition.
*
* @return an array {@code A} containing values {@code A[i] < base} such that
* \(\sum_i{ \text{A}[i] \cdot \text{base}^i} = \text{number}\)
* \(\sum_i{ \text{A}[i] \cdot \text{base}^i} = \text{number}\)
* @throws IllegalArgumentException if {@code numDigits} is not enough to represent the given number
*/
public static BigInteger[] decomposeIntoDigits(BigInteger number, BigInteger base, int numDigits) {
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