Data commit

2023-07-01 11:58:00 -04:00 · 2023-07-01 11:58:00 -04:00 · cb5bb5e222
commit cb5bb5e222
parent 7387c8f97b
199093 changed files with 3378972 additions and 0 deletions
--- a/Task/Brazilian-numbers/Java/brazilian-numbers.java
+++ b/Task/Brazilian-numbers/Java/brazilian-numbers.java
@ -0,0 +1,98 @@
+import java.math.BigInteger;
+import java.util.List;
+
+public class Brazilian {
+    private static final List<Integer> primeList = List.of(
+        2, 3, 5, 7, 9, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89,
+        97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181,
+        191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 247, 251, 257, 263, 269, 271, 277, 281,
+        283, 293, 299, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 377, 379, 383, 389,
+        397, 401, 403, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 481, 487, 491,
+        499, 503, 509, 521, 523, 533, 541, 547, 557, 559, 563, 569, 571, 577, 587, 593, 599, 601, 607,
+        611, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 689, 691, 701, 709, 719,
+        727, 733, 739, 743, 751, 757, 761, 767, 769, 773, 787, 793, 797, 809, 811, 821, 823, 827, 829,
+        839, 853, 857, 859, 863, 871, 877, 881, 883, 887, 907, 911, 919, 923, 929, 937, 941, 947, 949,
+        953, 967, 971, 977, 983, 991, 997
+    );
+
+    public static boolean isPrime(int n) {
+        if (n < 2) {
+            return false;
+        }
+
+        for (Integer prime : primeList) {
+            if (n == prime) {
+                return true;
+            }
+            if (n % prime == 0) {
+                return false;
+            }
+            if (prime * prime > n) {
+                return true;
+            }
+        }
+
+        BigInteger bi = BigInteger.valueOf(n);
+        return bi.isProbablePrime(10);
+    }
+
+    private static boolean sameDigits(int n, int b) {
+        int f = n % b;
+        while ((n /= b) > 0) {
+            if (n % b != f) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static boolean isBrazilian(int n) {
+        if (n < 7) return false;
+        if (n % 2 == 0) return true;
+        for (int b = 2; b < n - 1; ++b) {
+            if (sameDigits(n, b)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public static void main(String[] args) {
+        for (String kind : List.of("", "odd ", "prime ")) {
+            boolean quiet = false;
+            int bigLim = 99_999;
+            int limit = 20;
+            System.out.printf("First %d %sBrazilian numbers:\n", limit, kind);
+            int c = 0;
+            int n = 7;
+            while (c < bigLim) {
+                if (isBrazilian(n)) {
+                    if (!quiet) System.out.printf("%d ", n);
+                    if (++c == limit) {
+                        System.out.println("\n");
+                        quiet = true;
+                    }
+                }
+                if (quiet && !"".equals(kind)) continue;
+                switch (kind) {
+                    case "":
+                        n++;
+                        break;
+                    case "odd ":
+                        n += 2;
+                        break;
+                    case "prime ":
+                        do {
+                            n += 2;
+                        } while (!isPrime(n));
+                        break;
+                    default:
+                        throw new AssertionError("Oops");
+                }
+            }
+            if ("".equals(kind)) {
+                System.out.printf("The %dth Brazilian number is: %d\n\n", bigLim + 1, n);
+            }
+        }
+    }
+}