From 36c1692916b1b4784116dbd9e8af674a3feca447 Mon Sep 17 00:00:00 2001 From: Bert Peters Date: Mon, 16 Dec 2019 22:41:24 +0100 Subject: [PATCH] Reduce allocations even more. --- 2019/src/day16.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/2019/src/day16.cpp b/2019/src/day16.cpp index 27d892f..2ead298 100644 --- a/2019/src/day16.cpp +++ b/2019/src/day16.cpp @@ -88,17 +88,17 @@ void aoc2019::day16_part2(std::istream &input, std::ostream &output) { } numbers = std::vector(numbers.begin() + offset, numbers.end()); + std::vector new_numbers(numbers.size()); for (int i = 0; i < 100; ++i) { std::vector partial_sums = partial_sum(numbers); - std::vector new_numbers(numbers.size()); for (int j = 0; j < numbers.size(); ++j) { int n = partial_sums.back() - partial_sums[j] + numbers[j]; new_numbers[j] = std::abs(n % 10); } - numbers = new_numbers; + std::swap(numbers, new_numbers); } std::copy(numbers.begin(), numbers.begin() + 8, std::ostream_iterator(output));