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#include "aoc.h"
#include <algorithm>
#include <deque>
#include <iostream>
#include <set>
#include <vector>
namespace aoc2022 {
struct valve_m {
valve* v;
int m;
friend bool operator<(valve_m v1, valve_m v2) { return v1.m < v2.m ? true : v1.m > v2.m ? false : v1.v < v2.v; }
friend bool operator>(valve_m v1, valve_m v2) { return v1.m > v2.m ? true : v1.m < v2.m ? false : v1.v > v2.v; }
};
std::map<line_view, valve*> valves = {};
std::map<valve*, std::vector<valve_m>> diagram;
int maxopened = 0;
static valve* get(line_view lv) {
auto p = valves.insert({lv, nullptr});
return p.first->second;
}
// bfs Dijkstra’s algorithm
// You estimate it will take you one minute to open a single valve
// and one minute to follow any tunnel from one valve to another.
void rank_neighbours(valve* v, std::map<valve*, int>& visited) {
std::deque<valve*> q;
q.push_back(v);
visited.insert({v, 0});
while (!q.empty()) {
auto s = q.size();
while (s-- > 0) {
valve* vx = q.front();
q.pop_front();
for (auto& lv : vx->others) {
valve* vn = get(lv);
auto it = visited.find(vn);
int m = visited[vx] + 1;
if (it == visited.end()) {
visited.insert({vn, m});
q.push_back(vn);
} else {
if (m < it->second) {
it->second = m;
q.push_back(vn);
}
}
}
}
}
}
void update_total(int* total, std::map<valve*, int>& opened, int m) {
int t{0};
for (auto& kv : opened) {
t += kv.first->rate * (kv.second - m);
}
*total = t;
}
bool is_open(valve* v, const std::map<valve*, int>& opened) { return opened.find(v) != opened.end(); }
// m minutes left at v
void flow(int m, valve* v, std::map<valve*, int> opened, int os, int total, int* max) {
update_total(&total, opened, m);
if (m == 0) {
if (*max < total) {
*max = total;
}
} else {
if (os >= maxopened) {
flow(m - 1, v, opened, os, total, max);
} else {
if (!is_open(v, opened)) {
if (v->rate > 0) {
os += 1;
m -= 1;
}
opened.insert({v, m});
}
if (os >= maxopened) {
flow(m - 1, v, opened, os, total, max);
} else {
// choose next
auto f{false};
for (auto& n : diagram[v]) {
if (m >= n.m && !is_open(n.v, opened)) {
f = true;
flow(m - n.m, n.v, opened, os, total, max);
}
}
if (!f && m > 0) {
flow(m - 1, v, opened, os, total, max);
}
}
}
}
}
// struct valve_mm {
// valve_m vm1;
// valve_m vm2;
//
// friend bool operator<(valve_mm m1, valve_mm m2) {
// return m1.vm1 < m2.vm1 ? true : m1.vm1 > m2.vm1 ? false : m1.vm2 < m2.vm2;
// }
// };
std::vector<valve_m> cango(valve* v, int m0, int m, const std::map<valve*, int>& opened) {
std::vector<valve_m> t;
for (auto& vm : diagram[v]) {
if (!is_open(vm.v, opened) && m > vm.m && m == m0) {
t.emplace_back(vm);
}
}
return t;
}
void flow(int m, valve_m vs[2], std::map<int, int>& visited, std::map<valve*, int> opened, int os, int total,
int* max) {
update_total(&total, opened, m);
if (m == 0) {
if (*max < total) {
// printf("max is %d\n", total);
*max = total;
}
} else {
auto p = visited.insert({m, total});
if (!p.second) {
if (p.first->second > total) {
return;
}
p.first->second = total;
}
// std::cout << os << " opened, " << m << "/" << vs[0].m << "/" << vs[1].m << " m left, total " << total <<
// std::endl;
if (os >= maxopened) {
flow(m - 1, vs, visited, opened, os, total, max);
} else {
for (auto i = 0; i < 2; i++) {
if (vs[i].m == m && !is_open(vs[i].v, opened)) {
if (vs[i].v->rate > 0) {
os += 1;
vs[i].m -= 1;
}
// std::cout << vs[i].v->name << " opened with " << vs[i].m << " minutes left" << std::endl;
opened.insert({vs[i].v, vs[i].m});
}
}
if (os >= maxopened) {
flow(m - 1, vs, visited, opened, os, total, max);
} else {
auto ns0 = cango(vs[0].v, vs[0].m, m, opened);
auto ns1 = cango(vs[1].v, vs[1].m, m, opened);
if (ns0.size() == 0 && ns1.size() == 0) {
flow(m - 1, vs, visited, opened, os, total, max);
}
if (ns0.size() == 0 && ns1.size() > 0) {
for (auto& n : ns1) {
valve_m vx[2];
vx[0] = vs[0];
vx[1] = vs[1];
vx[1].m -= n.m;
vx[1].v = n.v;
auto v = visited;
flow(m - 1, vx, v, opened, os, total, max);
}
}
if (ns0.size() > 0 && ns1.size() == 0) {
for (auto& n : ns0) {
valve_m vx[2];
vx[0] = vs[0];
vx[1] = vs[1];
vx[0].m -= n.m;
vx[0].v = n.v;
auto v = visited;
flow(m - 1, vx, v, opened, os, total, max);
}
}
if (ns0.size() > 0 && ns1.size() > 0) {
for (auto& n0 : ns0) {
for (auto& n1 : ns1) {
if (n0.v != n1.v) {
valve_m vx[2];
vx[0] = vs[0];
vx[1] = vs[1];
vx[0].m -= n0.m;
vx[0].v = n0.v;
vx[1].m -= n1.m;
vx[1].v = n1.v;
auto v = visited;
flow(m - 1, vx, v, opened, os, total, max);
}
}
}
}
}
}
}
}
std::pair<int, int> day16(line_view file) {
per_line(file, [](line_view lv) {
valve* v = new valve{lv};
valves[v->name] = v;
if (v->rate > 0) {
maxopened += 1;
}
return true;
});
for (auto& kv : valves) {
valve* v = kv.second;
std::map<valve*, int> visited;
rank_neighbours(v, visited);
std::vector<valve_m> vs;
for (auto& kv : visited) {
if (kv.first != v && kv.first->rate > 0) {
vs.emplace_back(valve_m{kv.first, kv.second});
}
}
std::sort(vs.begin(), vs.end(), [](valve_m v1, valve_m v2) {
return v1.m < v2.m ? true : v1.m > v2.m ? false : v1.v->rate > v2.v->rate;
});
diagram.insert({v, vs});
}
// for (auto& kv : diagram) {
// std::cout << kv.first->name << ": ";
// for (auto& m : kv.second) {
// std::cout << m.v->name << "(" << m.m << "," << m.v->rate << ") ";
// }
// std::cout << std::endl;
// }
int m1{INT32_MIN};
std::map<valve*, int> opened;
flow(30, get("AA"), opened, 0, 0, &m1);
// opened.clear();
// int m2{INT32_MIN};
// valve_m vs[2] = {
// {get("AA"), 26},
// {get("AA"), 26},
// };
// std::map<int, int> visited;
// flow(26, vs, visited, opened, 0, 0, &m2);
return {m1, 1999};
}
} // namespace aoc2022
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