Merge pull request #9437 from mustafaaydn/challenge_252

Solutions for the 252nd challenge

4 files changed, 102 insertions, 0 deletions

diff --git a/challenge-252/witawayar/cpp/ch-1.cpp b/challenge-252/witawayar/cpp/ch-1.cpp
new file mode 100644
index 0000000000..2d06260474
--- /dev/null
+++ b/challenge-252/witawayar/cpp/ch-1.cpp
@@ -0,0 +1,38 @@
+// g++ -Wall -Wextra -Wpedantic -std=c++17 cpp/ch-1.cpp
+#include <algorithm>  // transform
+#include <iostream>   // cout
+#include <numeric>    // accumulate
+#include <sstream>    // stringstream
+#include <vector>
+
+int fun(std::vector<int> const& ints) {
+    std::vector<int> out;
+    const std::size_t N = ints.size();
+    std::vector<std::size_t> indexes(N);
+    std::iota(indexes.begin(), indexes.end(), 1u);
+    std::transform(ints.cbegin(), ints.cend(),
+                   indexes.cbegin(), std::back_inserter(out),
+                   [&](const int& value, const std::size_t& index) {
+                       return N % index == 0 ? value * value : 0; });
+
+    return std::accumulate(out.cbegin(), out.cend(), 0);
+}
+
+int main(void) {
+    // Tests
+    std::vector<std::pair<std::vector<int>, int>> tests = {
+        {{1, 2, 3, 4}, 21},
+        {{2, 7, 1, 19, 18, 3}, 63},
+    };
+
+    for (const auto& [input, expected_output] : tests) {
+        int got = fun(input);
+        if (got != expected_output) {
+            std::stringstream error_msg;
+            error_msg << "Expected " << expected_output << ", got " << got;
+            throw std::runtime_error(error_msg.str());
+        }
+    }
+
+    std::cout << "done-testing, success\n";
+}
diff --git a/challenge-252/witawayar/cpp/ch-2.cpp b/challenge-252/witawayar/cpp/ch-2.cpp
new file mode 100644
index 0000000000..91b103757b
--- /dev/null
+++ b/challenge-252/witawayar/cpp/ch-2.cpp
@@ -0,0 +1,28 @@
+// g++ -Wall -Wextra -Wpedantic -std=c++17 cpp/ch-2.cpp
+#include <iostream>   // cout
+#include <numeric>    // accumulate
+#include <sstream>    // stringstream
+#include <vector>
+
+std::vector<int> fun(int const& n) {
+    std::vector<int> range(n);
+    std::iota(range.begin(), range.end(), -(n / 2));
+    return range;
+}
+
+int main(void) {
+    // Tests
+    std::vector<unsigned> tests{5, 3, 1};
+
+    for (const unsigned& input : tests) {
+        std::vector<int> got = fun(input);
+        int sum = std::accumulate(got.cbegin(), got.cend(), 0);
+        if (sum != 0) {
+            std::stringstream error_msg;
+            error_msg << "Expected " << 0 << ", got " << sum;
+            throw std::runtime_error(error_msg.str());
+        }
+    }
+
+    std::cout << "done-testing, success\n";
+}
diff --git a/challenge-252/witawayar/raku/ch-1.raku b/challenge-252/witawayar/raku/ch-1.raku
new file mode 100644
index 0000000000..c79a1fe59f
--- /dev/null
+++ b/challenge-252/witawayar/raku/ch-1.raku
@@ -0,0 +1,22 @@
+my &fun = { @^ints.kv.map({ $^value ** 2 if +@ints %% $^index.succ }).sum }
+
+#`{
+- Take an array of things via the implicit signature @^ints
+- Reach its "keys" and "values" via `.kv`
+    - Keys are the 0-based indexes, values are, well, the values themselves
+    - This gives a 2N length sequence
+- We can `.map` the interleaved key-value sequence via an implicit signature
+    - Lexicographically, index < value, so when taking 2 things at a time (since arity == 2),
+      `.map` will assign the first one (key) to $^index, second one (value) to $^value
+- Then accumulate value squared if index's "succ"essor (index + 1) is a divisor of @^ints' length
+}
+
+use Test;
+my @tests of Pair =
+    (1, 2, 3, 4) => 21,
+    (2, 7, 1, 19, 18, 3) => 63;
+
+for @tests -> (:key($input), :value($expected-output)) {
+    ok fun($input) eqv $expected-output;
+    LAST done-testing;
+}
diff --git a/challenge-252/witawayar/raku/ch-2.raku b/challenge-252/witawayar/raku/ch-2.raku
new file mode 100644
index 0000000000..238397366d
--- /dev/null
+++ b/challenge-252/witawayar/raku/ch-2.raku
@@ -0,0 +1,14 @@
+my &fun = { list -$_ .. $_ given $^n div 2 }
+
+#`{
+- Take a scalar via the implicit signature $^n
+- Floor-divide it by 2, and the range between minus that and itself satisfies the condition
+}
+
+use Test;
+my @tests of UInt = 5, 3, 1;
+
+for @tests -> $n {
+    ok fun($n).sum == 0;
+    LAST done-testing;
+}