Merge pull request #4966 from andinus/master

Add solutions for challenge 133

5 files changed, 158 insertions, 23 deletions

diff --git a/challenge-133/andinus/README b/challenge-133/andinus/README
index 7e67d6381d..93034423ed 100644
--- a/challenge-133/andinus/README
+++ b/challenge-133/andinus/README
@@ -1,51 +1,81 @@
                             ━━━━━━━━━━━━━━━
-                             CHALLENGE 130
+                             CHALLENGE 133
 
                                 Andinus
                             ━━━━━━━━━━━━━━━
 
 
-                               2021-09-14
+                               2021-10-04
 
 
-Table of Contents
-─────────────────
 
-Task 1 - Odd Number
 
 
+Task 1 - Integer Square Root
+════════════════════════════
 
+  You are given a positive integer `$N'.
 
+  Write a script to calculate the integer square root of the given
+  number.
 
-Task 1 - Odd Number
-═══════════════════
+  Please avoid using built-in function. Find out more about it [here].
 
-  You are given an array of positive integers, such that all the numbers
-  appear even number of times except one number.
-
-  Write a script to find that integer.
-
-  Examples:
   ┌────
-  │ Input: @N = (2, 5, 4, 4, 5, 5, 2)
-  │ Output: 5 as it appears 3 times in the array where as all other numbers 2 and 4 appears exactly twice.
+  │ Input: $N = 10
+  │ Output: 3
+  │
+  │ Input: $N = 27
+  │ Output: 5
+  │
+  │ Input: $N = 85
+  │ Output: 9
   │
-  │ Input: @N = (1, 2, 3, 4, 3, 2, 1, 4, 4)
-  │ Output: 4
+  │ Input: $N = 101
+  │ Output: 10
   └────
 
 
+[here] <https://en.wikipedia.org/wiki/Integer_square_root>
+
 Raku
 ────
 
   • Program: <file:raku/ch-1.raku>
 
-  `@nums' holds the input and `%seen' is True if it's seen odd number of
-  times. We loop over `@nums' and invert the value of that number in
-  `%seen'.
+  Initial estimate is set to `$n +> 1', then we loop infinitely until
+  previous 2 estimates are equal.
+
+  ┌────
+  │ my $x = $n +> 1;
+  │ loop {
+  │     given ($x + ($n / $x)) / 2 {
+  │         last if $x == $_;
+  │         $x = $_;
+  │     }
+  │ }
+  │ put $x;
+  └────
+
+
+C
+─
+
+  • Program: <file:c/ch-1.c>
+
+  `argv' holds the input & `argc' holds the number of inputs. The input
+  should be a single integer so `argc' should be equal to 2. After
+  checking for that, we check if valid value was passed.
+
+  Loop until previous 2 estimates are equal.
 
   ┌────
-  │ my Bool %seen;
-  │ %seen{$_} = !%seen{$_} for @nums;
-  │ put %seen.grep(*.value).map(*.key);
+  │ double x = num >> 1;
+  │ for (;;) {
+  │     double x_next = (x + (num / x)) / 2;
+  │     if (x == x_next)
+  │         break;
+  │     x = x_next;
+  │  }
+  │ printf("%f\n", x);
   └────
diff --git a/challenge-133/andinus/README.org b/challenge-133/andinus/README.org
new file mode 100644
index 0000000000..a8c25aedc3
--- /dev/null
+++ b/challenge-133/andinus/README.org
@@ -0,0 +1,67 @@
+#+title: Challenge 133
+#+date: 2021-10-04
+#+html_link_up: ../
+#+export_file_name: index
+#+options: toc:nil
+#+setupfile: ~/.emacs.d/org-templates/level-2.org
+
+* Task 1 - Integer Square Root
+
+You are given a positive integer ~$N~.
+
+Write a script to calculate the integer square root of the given number.
+
+Please avoid using built-in function. Find out more about it [[https://en.wikipedia.org/wiki/Integer_square_root][here]].
+
+#+begin_src
+Input: $N = 10
+Output: 3
+
+Input: $N = 27
+Output: 5
+
+Input: $N = 85
+Output: 9
+
+Input: $N = 101
+Output: 10
+#+end_src
+
+** Raku
+
+- Program: [[file:raku/ch-1.raku]]
+
+Initial estimate is set to ~$n +> 1~, then we loop infinitely until
+previous 2 estimates are equal.
+
+#+begin_src raku
+my $x = $n +> 1;
+loop {
+    given ($x + ($n / $x)) / 2 {
+        last if $x == $_;
+        $x = $_;
+    }
+}
+put $x;
+#+end_src
+
+** C
+
+- Program: [[file:c/ch-1.c]]
+
+~argv~ holds the input & ~argc~ holds the number of inputs. The input should
+be a single integer so ~argc~ should be equal to 2. After checking for
+that, we check if valid value was passed.
+
+Loop until previous 2 estimates are equal.
+
+#+begin_src c
+double x = num >> 1;
+for (;;) {
+    double x_next = (x + (num / x)) / 2;
+    if (x == x_next)
+        break;
+    x = x_next;
+ }
+printf("%f\n", x);
+#+end_src
diff --git a/challenge-133/andinus/blog-1.txt b/challenge-133/andinus/blog-1.txt
new file mode 100644
index 0000000000..cd040d689d
--- /dev/null
+++ b/challenge-133/andinus/blog-1.txt
@@ -0,0 +1 @@
+https://andinus.unfla.me/pwc/challenge-133/
diff --git a/challenge-133/andinus/c/ch-1.c b/challenge-133/andinus/c/ch-1.c
new file mode 100644
index 0000000000..f28d6d9355
--- /dev/null
+++ b/challenge-133/andinus/c/ch-1.c
@@ -0,0 +1,26 @@
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <limits.h>
+
+int main(int argc, char *argv[]) {
+    if (argc != 2) {
+        puts("Usage: ./ch-1 <positive number>");
+        exit(0);
+    }
+
+    const char *errstr;
+    long num = strtonum(argv[1], 1, LONG_MAX, &errstr);
+    if (errstr != NULL)
+        errx(1, "number is %s: %s", errstr, argv[1]);
+
+    double x = num >> 1;
+    for (;;) {
+        double x_next = (x + (num / x)) / 2;
+        if (x == x_next)
+            break;
+        x = x_next;
+    }
+    printf("%f\n", x);
+}
diff --git a/challenge-133/andinus/raku/ch-1.raku b/challenge-133/andinus/raku/ch-1.raku
new file mode 100644
index 0000000000..cde47fcabe
--- /dev/null
+++ b/challenge-133/andinus/raku/ch-1.raku
@@ -0,0 +1,11 @@
+#| Integer Square Root
+sub MAIN(UInt $n) {
+    my $x = $n +> 1;
+    loop {
+        given ($x + ($n / $x)) / 2 {
+            last if $x == $_;
+            $x = $_;
+        }
+    }
+    put $x;
+}