From 106f049577d95aba22c1b9a7d03326a057ca385c Mon Sep 17 00:00:00 2001
From: vil02 <65706193+vil02@users.noreply.github.com>
Date: Fri, 27 Sep 2024 19:35:42 +0200
Subject: [PATCH] style: use `std::transform_reduce`

---
 dynamic_programming/catalan_numbers.cpp | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/dynamic_programming/catalan_numbers.cpp b/dynamic_programming/catalan_numbers.cpp
index b37f43a4e7..c99ea00265 100644
--- a/dynamic_programming/catalan_numbers.cpp
+++ b/dynamic_programming/catalan_numbers.cpp
@@ -12,6 +12,7 @@
 #include <cassert>  /// for assert
 #include <cstdint>  /// for std::uint64_t
 #include <cstdlib>  /// for std::size_t
+#include <numeric>  /// for std::transform_reduce
 #include <vector>   /// for std::vector
 
 /**
@@ -22,11 +23,9 @@ class catalan_numbers {
     std::vector<value_type> known{1, 1};
 
     value_type compute_next() {
-        value_type res = 0;
-        for (std::size_t i = 0; i < known.size(); ++i) {
-            res += known[i] * known[known.size() - i - 1];
-        }
-        return res;
+        return std::transform_reduce(known.begin(), known.end(), known.rbegin(),
+                                     static_cast<value_type>(), std::plus<>(),
+                                     std::multiplies<>());
     }
 
     void add() { known.push_back(this->compute_next()); }