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#pragma once
#include "common.h"
#include <algorithm>
#include <functional>
#include <vector>
namespace aoc2019 {
struct day3point {
int x;
int y;
int distance() const noexcept { return std::abs(x) + std::abs(y); }
bool operator<(const day3point& other) const noexcept { return distance() < other.distance(); }
};
struct wire {
struct part {
enum dir_t {
up,
right,
down,
left,
} dir;
int distance;
};
day3point mov(day3point p, part pa) const noexcept {
auto addy = [&p](int d) -> day3point { return {p.x, p.y + d}; };
auto addx = [&p](int d) -> day3point { return {p.x + d, p.y}; };
auto suby = [&p](int d) -> day3point { return {p.x, p.y - d}; };
auto subx = [&p](int d) -> day3point { return {p.x - d, p.y}; };
std::function<day3point(int)> fs[] = {addy, addx, suby, subx};
return fs[int(pa.dir)](pa.distance);
}
struct line {
int id;
line_view label;
day3point a;
day3point b;
int length;
};
std::vector<line> psh;
std::vector<line> psv;
std::vector<line> ps;
void sort() {
std::sort(psh.begin(), psh.end(),
[](const line& l1, const line& l2) { return std::abs(l1.a.y) < std::abs(l2.a.y); });
std::sort(psv.begin(), psv.end(),
[](const line& l1, const line& l2) { return std::abs(l1.a.x) < std::abs(l2.a.x); });
}
void get_part(const char** pp, int* d) {
*d = 0;
const char* p = *pp + 1;
while (*p >= '0' && *p <= '9') {
*d = *d * 10 + *p - '0';
p++;
}
*pp = p;
}
void parse(line_view lv, day3point* cp) {
part p;
const char* p1 = lv.line;
int i{0};
auto make_part = [&i, &p, &p1, cp, this](part::dir_t d) {
p.dir = d;
const char* p0 = p1;
get_part(&p1, &p.distance);
day3point a = *cp;
*cp = mov(*cp, p);
line l{i++, {p0, p1}, a, *cp, p.distance};
ps.push_back(l);
if (d == part::right || d == part::left) {
psh.push_back(l);
}
if (d == part::up || d == part::down) {
psv.push_back(l);
}
};
while (p1 < lv.line + lv.length) {
switch (*p1) {
case 'R':
make_part(part::right);
break;
case 'L':
make_part(part::left);
break;
case 'U':
make_part(part::up);
break;
case 'D':
make_part(part::down);
break;
default:
break;
}
p1++;
}
}
};
std::pair<int, int> day3(line_view);
} // namespace aoc2019
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