Random Latin squares: Difference between revisions
Content deleted Content added
Line 729:
4 2 3 1 5 0
</pre>
=={{header|Java}}==
{{trans|Kotlin}}
<lang java>import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
public class RandomLatinSquares {
private static void printSquare(List<List<Integer>> latin) {
for (List<Integer> row : latin) {
Iterator<Integer> it = row.iterator();
System.out.print("[");
if (it.hasNext()) {
Integer col = it.next();
System.out.print(col);
}
while (it.hasNext()) {
Integer col = it.next();
System.out.print(", ");
System.out.print(col);
}
System.out.println("]");
}
System.out.println();
}
private static void latinSquare(int n) {
if (n <= 0) {
System.out.println("[]");
return;
}
List<List<Integer>> latin = new ArrayList<>(n);
for (int i = 0; i < n; ++i) {
List<Integer> inner = new ArrayList<>(n);
for (int j = 0; j < n; ++j) {
inner.add(j);
}
latin.add(inner);
}
// first row
Collections.shuffle(latin.get(0));
// middle row(s)
for (int i = 1; i < n - 1; ++i) {
boolean shuffled = false;
shuffling:
while (!shuffled) {
Collections.shuffle(latin.get(i));
for (int k = 0; k < i; ++k) {
for (int j = 0; j < n; ++j) {
if (Objects.equals(latin.get(k).get(j), latin.get(i).get(j))) {
continue shuffling;
}
}
}
shuffled = true;
}
}
// last row
for (int j = 0; j < n; ++j) {
List<Boolean> used = new ArrayList<>(n);
for (int i = 0; i < n; ++i) {
used.add(false);
}
for (int i = 0; i < n - 1; ++i) {
used.set(latin.get(i).get(j), true);
}
for (int k = 0; k < n; ++k) {
if (!used.get(k)) {
latin.get(n - 1).set(j, k);
break;
}
}
}
printSquare(latin);
}
public static void main(String[] args) {
latinSquare(5);
latinSquare(5);
latinSquare(10);
}
}</lang>
{{out}}
<pre>[1, 3, 4, 0, 2]
[4, 0, 2, 1, 3]
[0, 2, 1, 3, 4]
[2, 1, 3, 4, 0]
[3, 4, 0, 2, 1]
[4, 2, 1, 3, 0]
[2, 1, 3, 0, 4]
[0, 3, 2, 4, 1]
[3, 4, 0, 1, 2]
[1, 0, 4, 2, 3]
[8, 7, 9, 0, 1, 2, 6, 5, 4, 3]
[4, 6, 3, 8, 0, 5, 2, 9, 1, 7]
[2, 1, 0, 4, 8, 9, 7, 3, 5, 6]
[6, 4, 8, 1, 9, 7, 3, 0, 2, 5]
[7, 9, 2, 6, 5, 3, 4, 8, 0, 1]
[9, 5, 1, 3, 2, 6, 8, 4, 7, 0]
[5, 0, 4, 9, 6, 8, 1, 7, 3, 2]
[3, 8, 5, 2, 7, 1, 0, 6, 9, 4]
[1, 3, 6, 7, 4, 0, 5, 2, 8, 9]
[0, 2, 7, 5, 3, 4, 9, 1, 6, 8]</pre>
=={{header|Javascript}}==
| |||