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#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <map>
#include "../utils.h"
class Line {
public:
Line (int a, int b, int c, int d) : a(a), b(b), c(c), d(d) { }
Line (std::string line) {
std::vector<std::string> parts, start, end;
split(parts, line, "->");
split(start, parts[0], ",");
split(end, parts[1], ",");
a = std::stoi(start[0]);
b = std::stoi(start[1]);
c = std::stoi(end[0]);
d = std::stoi(end[1]);
if (c-a == 0) xdir = 0;
else { xdir = (c-a) > 0 ? 1 : -1; }
if (d-b == 0) ydir = 0;
else { ydir = (d-b) > 0 ? 1 : -1; }
}
int a, b, c, d, xdir, ydir;
int length () { return abs(a-c) + abs(b-d); }
bool operator==(Line& oth) {
return a == oth.a && b == oth.b && c == oth.c && d == oth.d;
}
};
int main (int argc, char *argv[]) {
std::string raw;
std::getline(std::ifstream(argv[1]), raw, '\0');
std::vector<Line> lines;
std::vector<std::string> strlines;
split(strlines, raw, "\n");
for (auto strline : strlines) {
if (strline.size() == 0) continue;
Line line { strline };
if (line.xdir != 0 && line.ydir != 0
&& std::stoi(argv[2]) == 0) continue;
lines.push_back(line);
}
int intersections = 0;
std::map<std::pair<int, int>, int> overlaps;
for (auto& line : lines) {
int dist = 0;
bool straight = true;
if (line.xdir != 0 && line.ydir != 0) straight = false;
for (int i=0; dist<line.length()+1; i++) {
std::pair pair { line.a + line.xdir*i, line.b + line.ydir*i };
if (overlaps.count(pair) == 0) overlaps[pair] = 1;
else {
if (overlaps[pair] == 1) intersections += 1;
overlaps[pair] += 1;
}
if (straight) dist ++;
else dist += 2;
}
}
int minx = 200;
int maxx = -200;
int miny = 200;
int maxy = -200;
for (auto& line : lines) {
minx = std::min(minx, std::min(line.a, line.c));
maxx = std::max(maxx, std::max(line.a, line.c));
miny = std::min(miny, std::min(line.b, line.d));
maxy = std::max(maxy, std::max(line.b, line.d));
}
std::cout << "bounds: "
<< minx << " " << maxx << " "
<< miny << " " << maxx << std::endl;
/* visualizer
for (int y=miny; y<maxy+1; y++) {
for (int x=minx; x<maxx+1; x++) {
int amt = overlaps[std::make_pair(x, y)];
if (amt > 9) amt = 9;
if (amt > 0) std::cout << amt;
else std::cout << ".";
}
std::cout << std::endl;
}
*/
std::cout << "intersections: " << intersections << std::endl;
return 0;
}
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