From dd2a41d26cfab5d551a88ff16d0b6062518d34e0 Mon Sep 17 00:00:00 2001
From: Paulo Custodio <pauloscustodio@gmail.com>
Date: Thu, 24 Jun 2021 19:43:49 +0100
Subject: Add bc solution to challenge 008

---
 challenge-008/paulo-custodio/bc/ch-1.bc | 49 +++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 challenge-008/paulo-custodio/bc/ch-1.bc

diff --git a/challenge-008/paulo-custodio/bc/ch-1.bc b/challenge-008/paulo-custodio/bc/ch-1.bc
new file mode 100644
index 0000000000..12053a2445
--- /dev/null
+++ b/challenge-008/paulo-custodio/bc/ch-1.bc
@@ -0,0 +1,49 @@
+#!/usr/bin/bc -ql
+
+/*
+Challenge 008
+
+Challenge #1
+Write a script that computes the first five perfect numbers. A perfect number
+is an integer that is the sum of its positive proper divisors (all divisors
+except itself). Please check Wiki for more information.
+This challenge was proposed by Laurent Rosenfeld.
+*/
+
+scale = 0
+
+num = read()
+
+define is_prime(n) {
+    auto i
+    if (n <= 1) return 0
+    if (n <= 3) return 1
+    if ((n % 2) == 0 || (n % 3) == 0) return 0
+    for (i = 5; i*i <= n; i += 6) {
+        if ((n % i) == 0 || (n % (i + 2)) == 0) return 0
+    }
+    return 1
+}
+
+define next_prime(n) {
+    if (n <= 1) return 2
+    n = n+1
+    while (!is_prime(n)) n = n+1
+    return n;
+}
+
+p = 1
+define next_perfect() {
+    auto f
+    while (1) {
+        p = next_prime(p)
+        f = (2 ^ p) - 1
+        if (is_prime(f)) return (2 ^ (p-1)) * f
+    }
+}
+
+for (i = 0; i < num; i++) {
+    print next_perfect(), "\n"
+}
+
+quit
-- 
cgit