155 lines
3.2 KiB
C++
155 lines
3.2 KiB
C++
#include <iostream>
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#include <fstream>
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#include <sstream>
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#include <string>
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#include <vector>
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#include <unordered_map>
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#include <algorithm>
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std::vector<std::string> tokenise( std::string input )
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{
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std::stringstream ssInput( input );
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std::vector<std::string> stream;
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std::string s;
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while( std::getline( ssInput, s, ',' ) ) {
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stream.push_back( s );
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}
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return stream;
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}
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struct vec2
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{
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int x;
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int y;
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bool operator==(const vec2& v) const
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{
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return x == v.x && y == v.y;
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}
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};
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namespace std
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{
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template <>
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struct hash<vec2>
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{
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size_t operator()( const vec2& v ) const
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{
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return v.x ^ v.y;
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}
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};
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}
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struct Wire
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{
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vec2 Head = { 0, 0 };
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vec2 Origin = { 0, 0 };
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std::vector<vec2> Visited;
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};
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void step( std::vector<vec2>& path, vec2& pos, int steps, char dir )
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{
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auto up = []( vec2& p ) { p.y -= 1; };
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auto down = []( vec2& p ) { p.y += 1; };
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auto left = []( vec2& p ) { p.x -= 1; };
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auto right = []( vec2& p ) { p.x += 1; };
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void (*stepSingle)(vec2&);
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switch ( dir )
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{
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case 'U': stepSingle = up; break;
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case 'D': stepSingle = down; break;
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case 'R': stepSingle = right; break;
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case 'L': stepSingle = left; break;
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default: break;
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}
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for( int i = 0; i < steps; i++ )
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{
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stepSingle( pos );
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path.push_back( pos );
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}
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}
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int main(int argc, char** argv)
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{
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std::ifstream infile( argv[1] );
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std::string input;
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std::getline( infile, input );
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std::vector<std::string> wireS1 = tokenise( input );
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std::getline( infile, input );
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std::vector<std::string> wireS2 = tokenise( input );
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// Construct map of nodes
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// for each point a wire
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// lays on, one is added
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// to the node
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// Wires are assumed to start at 0,0
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Wire wire1;
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for ( auto& element : wireS1 )
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{
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// Seperate the direction from the displacement
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char direction = element[0];
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int displacement = std::stoi( element.substr( 1, element.size() ) );
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step(wire1.Visited, wire1.Head, displacement, direction);
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std::cout << "Wire 1 " << element << std::endl;
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}
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Wire wire2;
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for ( auto& element : wireS2 )
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{
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// Seperate the direction from the displacement
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char direction = element[0];
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int displacement = std::stoi( element.substr( 1, element.size() ) );
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step(wire2.Visited, wire2.Head, displacement, direction);
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std::cout << "Wire 2 " << element << std::endl;
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}
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auto find = []( std::vector<vec2> arr, vec2 el ) {
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for ( int i = 0; i < arr.size(); i++ )
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if ( arr[i] == el ) return i;
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return -1;
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};
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std::vector<int> intersectDistances;
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// This takes a good few seconds
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for ( int i = 0; i < wire1.Visited.size(); i++ )
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{
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vec2 v = wire1.Visited[i];
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if ( find( wire2.Visited, v ) != -1 )
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{
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std::cout << "Found : " << v.x << " " << v.y << std::endl;
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intersectDistances.push_back( std::abs( v.x ) + std::abs( v.y ) );
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}
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}
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int minDistance = *std::min_element( intersectDistances.cbegin(), intersectDistances.cend() );
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std::cout << "Minimum Distance to Intersect : " << minDistance << std::endl;
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}
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