57 lines
1.3 KiB
C++
57 lines
1.3 KiB
C++
//
|
|
// Created by Matthew Gretton-Dann on 01/12/2022.
|
|
//
|
|
|
|
#include <algorithm>
|
|
#include <cstdlib>
|
|
#include <iomanip>
|
|
#include <iostream>
|
|
#include <numeric>
|
|
#include <utility>
|
|
|
|
using UInt = std::uint64_t;
|
|
|
|
using namespace std::string_literals;
|
|
|
|
auto amend_polymer(std::string polymer, char remove) -> std::string
|
|
{
|
|
auto it{std::remove_if(polymer.begin(), polymer.end(),
|
|
[remove](auto c) { return c == remove || (c == std::toupper(remove)); })};
|
|
return {polymer.begin(), it};
|
|
}
|
|
|
|
auto react_polymer(std::string polymer) -> UInt
|
|
{
|
|
auto it{polymer.begin()};
|
|
while ((it + 1) != polymer.end()) {
|
|
if (*it != *(it + 1) && (*it == std::tolower(*(it + 1)) || *it == std::toupper(*(it + 1)))) {
|
|
it = polymer.erase(it, it + 2);
|
|
if (it != polymer.begin()) {
|
|
--it;
|
|
}
|
|
}
|
|
else {
|
|
++it;
|
|
}
|
|
}
|
|
return polymer.size();
|
|
}
|
|
|
|
auto main() -> int
|
|
{
|
|
std::string polymer;
|
|
|
|
if (!std::getline(std::cin, polymer)) {
|
|
std::cout << "Unable to read line.\n";
|
|
return EXIT_FAILURE;
|
|
}
|
|
|
|
UInt min_length{polymer.size() + 1};
|
|
for (char c{'a'}; c < 'z' + 1; ++c) {
|
|
std::string const poly2{amend_polymer(polymer, c)};
|
|
min_length = std::min(min_length, react_polymer(poly2));
|
|
}
|
|
std::cout << "Minimum length: " << min_length << "\n";
|
|
return EXIT_SUCCESS;
|
|
}
|