Created
March 7, 2021 21:04
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Algorithm for iterating through combinations of numbers
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import java.util.ArrayList; | |
import java.util.Arrays; | |
import java.util.List; | |
import java.util.stream.Collectors; | |
public class CombinationGetter { | |
public List<int[]> getCombinations(final int n, final int min, final int k) { | |
final List<int[]> list = new ArrayList<>(); | |
int temp; | |
final int[] a = new int[n]; | |
Arrays.fill(a, min); | |
a[n - 1] = 0; | |
temp = n - 1; | |
while (true) { | |
if (a[temp] == k) { | |
temp--; | |
if (temp < 0) break; | |
} else { | |
a[temp]++; | |
while (temp + 1 < n) { | |
temp++; | |
a[temp] = 1; | |
} | |
list.add(Arrays.copyOf(a, n)); | |
} | |
} | |
return list; | |
} | |
public static void main(final String... args) { | |
System.out.println("Ciao Mondo!"); | |
final CombinationGetter comboGetter = new CombinationGetter(); | |
System.out.println( | |
comboGetter | |
.getCombinations(4, 1, 6) | |
.stream() | |
.map(Arrays::toString) | |
.collect(Collectors.joining("\n"))); | |
} | |
} |
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