Upload files to "java/base"

2026-04-13 10:38:03 +03:00
parent 9a225ab16a
commit b47fd19096
5 changed files with 514 additions and 0 deletions
--- a/java/base/ExtendedRandom.java
+++ b/java/base/ExtendedRandom.java
@@ -0,0 +1,103 @@
+package base;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+/**
+ * @author Georgiy Korneev (kgeorgiy@kgeorgiy.info)
+ */
+public final class ExtendedRandom {
+
+    public static final String ENGLISH = "abcdefghijklmnopqrstuvwxyz";
+    public static final String RUSSIAN = "абвгдеежзийклмнопрстуфхцчшщъыьэюя";
+    public static final String GREEK = "αβγŋδεζηθικλμνξοπρτυφχψω";
+
+    @SuppressWarnings("StaticMethodOnlyUsedInOneClass")
+    public static final String SPACES = " \t\n\u000B\u2029\f";
+
+    private final Random random;
+
+    public ExtendedRandom(final Random random) {
+        this.random = random;
+    }
+
+    public ExtendedRandom(final Class<?> owner) {
+        this(new Random(7912736473497634913L + owner.getName().hashCode()));
+    }
+
+    public String randomString(final String chars) {
+        return (
+            randomChar(chars) +
+            (random.nextBoolean() ? "" : randomString(chars))
+        );
+    }
+
+    public char randomChar(final String chars) {
+        return chars.charAt(nextInt(chars.length()));
+    }
+
+    public String randomString(final String chars, final int length) {
+        final StringBuilder string = new StringBuilder();
+        for (int i = 0; i < length; i++) {
+            string.append(randomChar(chars));
+        }
+        return string.toString();
+    }
+
+    public String randomString(
+        final String chars,
+        final int minLength,
+        final int maxLength
+    ) {
+        return randomString(chars, nextInt(minLength, maxLength));
+    }
+
+    public boolean nextBoolean() {
+        return random.nextBoolean();
+    }
+
+    public int nextInt() {
+        return random.nextInt();
+    }
+
+    public int nextInt(final int min, final int max) {
+        return nextInt(max - min + 1) + min;
+    }
+
+    public int nextInt(final int n) {
+        return random.nextInt(n);
+    }
+
+    @SafeVarargs
+    public final <T> T randomItem(final T... items) {
+        return items[nextInt(items.length)];
+    }
+
+    public <T> T randomItem(final List<T> items) {
+        return items.get(nextInt(items.size()));
+    }
+
+    public Random getRandom() {
+        return random;
+    }
+
+    public <T> List<T> random(
+        final int list,
+        final Function<ExtendedRandom, T> generator
+    ) {
+        return Stream.generate(() -> generator.apply(this))
+            .limit(list)
+            .toList();
+    }
+
+    public double nextDouble() {
+        return random.nextDouble();
+    }
+
+    public <E> void shuffle(final List<E> all) {
+        Collections.shuffle(all, random);
+    }
+}