109 lines
2.7 KiB
C++
109 lines
2.7 KiB
C++
//
|
|
// Created by Matthew Gretton-Dann on 08/12/2022.
|
|
//
|
|
|
|
#include <cassert>
|
|
#include <complex>
|
|
#include <iostream>
|
|
#include <map>
|
|
#include <numeric>
|
|
#include <string>
|
|
#include <utility>
|
|
|
|
using UInt = std::uint64_t;
|
|
using Pos = std::complex<UInt>;
|
|
using Data = std::pair<UInt, bool>;
|
|
|
|
struct compare_pos
|
|
{
|
|
constexpr auto operator()(Pos const& l, Pos const& r) const noexcept
|
|
{
|
|
if (l.imag() < r.imag()) {
|
|
return true;
|
|
}
|
|
if (l.imag() == r.imag() && l.real() < r.real()) {
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
};
|
|
|
|
auto main() -> int
|
|
{
|
|
std::string line;
|
|
Pos grid_size{0, 0};
|
|
std::map<Pos, Data, compare_pos> trees;
|
|
|
|
while (std::getline(std::cin, line) && !line.empty()) {
|
|
Pos pos{0, grid_size.imag()};
|
|
assert(grid_size.real() == 0 || grid_size.real() == line.size());
|
|
for (auto c : line) {
|
|
trees.insert({pos, Data{static_cast<UInt>(c - '0'), false}});
|
|
pos += 1;
|
|
}
|
|
grid_size = pos + Pos{0, 1};
|
|
}
|
|
|
|
for (UInt j = 0; j < grid_size.imag(); ++j) {
|
|
UInt min{0};
|
|
for (UInt i{0}; i < grid_size.real(); ++i) {
|
|
auto it{trees.find(Pos{i, j})};
|
|
assert(it != trees.end());
|
|
if (it->second.first >= min) {
|
|
min = it->second.first + 1;
|
|
it->second.second = true;
|
|
}
|
|
}
|
|
min = 0;
|
|
for (UInt i{grid_size.real()}; i > 0; --i) {
|
|
auto it{trees.find(Pos{i - 1, j})};
|
|
assert(it != trees.end());
|
|
if (it->second.first >= min) {
|
|
min = it->second.first + 1;
|
|
it->second.second = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (UInt i = 0; i < grid_size.real(); ++i) {
|
|
UInt min{0};
|
|
for (UInt j{0}; j < grid_size.imag(); ++j) {
|
|
auto it{trees.find(Pos{i, j})};
|
|
assert(it != trees.end());
|
|
if (it->second.first >= min) {
|
|
min = it->second.first + 1;
|
|
it->second.second = true;
|
|
}
|
|
}
|
|
min = 0;
|
|
for (UInt j{grid_size.imag()}; j > 0; --j) {
|
|
auto it{trees.find(Pos{i, j - 1})};
|
|
assert(it != trees.end());
|
|
if (it->second.first >= min) {
|
|
min = it->second.first + 1;
|
|
it->second.second = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
auto visible_count{
|
|
std::accumulate(trees.begin(), trees.end(), UInt{0},
|
|
[](UInt a, auto const& node) { return node.second.second ? (a + 1) : a; })};
|
|
std::cout << "Number visible " << visible_count << '\n';
|
|
#if 0
|
|
for (UInt j{0}; j != grid_size.imag(); ++j) {
|
|
for (UInt i{0}; i != grid_size.imag(); ++i) {
|
|
std::cout << trees.find({i, j})->second.first;
|
|
}
|
|
std::cout << '\n';
|
|
}
|
|
for (UInt j{0}; j != grid_size.imag(); ++j) {
|
|
for (UInt i{0}; i != grid_size.imag(); ++i) {
|
|
std::cout << (trees.find({i, j})->second.second ? '*' : '.');
|
|
}
|
|
std::cout << '\n';
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|