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Completed day 13 p1 and day 14

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Gnarwhal 2020-12-13 23:08:32 -08:00
parent a9d41ba4fd
commit a359db13b2
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106
2020/days/day13.cpp Normal file
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/*******************************************************************************
*
* Copyright (c) 2020 Gnarwhal
*
* -----------------------------------------------------------------------------
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files(the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*******************************************************************************/
#include <vector>
#include <string>
#include <iostream>
#include <fstream>
#include "../misc/types.hpp"
#include "../misc/print.hpp"
struct Pair{ u64 id; usize index; };
auto find_least(u64 new_base, u64 new_loop, u64 req_base, u64 req_loop, u64 iter) -> u64 {
while ((new_base + ++iter * new_loop - req_base) % req_loop != 0);
return new_base + iter * new_loop;
}
auto day13() -> void {
auto ready = usize(0);
auto buses = std::vector<Pair>();
{
auto line = std::string();
auto file = std::ifstream("inputs/day13.input");
getline(file, line);
ready = std::stoi(line);
getline(file, line);
auto start = usize(0);
auto end = usize(0);
auto index = usize(0);
auto id = std::string();
while ((end = line.find(',', start)) != std::string::npos) {
id = line.substr(start, end - start);
if (id != "x") {
buses.push_back({ u64(std::stoi(line.substr(start, end - start))), index });
}
start = end + 1;
++index;
}
end = line.size();
id = line.substr(start, end - start);
if (id != "x") {
buses.push_back({ u64(std::stoi(line.substr(start, end - start))), index });
}
}
auto id = buses[0].id;
auto minutes = buses[0].id - (ready % buses[0].id);
for (auto i = usize(1); i < buses.size(); ++i) {
auto local_minutes = buses[i].id - (ready % buses[i].id);
if (local_minutes < minutes) {
id = buses[i].id;
minutes = local_minutes;
}
}
print((id * minutes));
auto req_base = usize(0);
auto req_loop = usize(1);
for (auto i = usize(1); i < buses.size(); ++i) {
auto base_loop = usize(-1);
while ((++base_loop * buses[0].id + buses[i].index) % buses[i].id != 0);
auto rep_loop = usize(0);
while ((++rep_loop * buses[0].id) % buses[i].id != 0);
req_base = find_least(base_loop, rep_loop, req_base, req_loop, -1);
if (i < buses.size() - 1) {
req_loop = find_least(0, rep_loop, 0, req_loop, 0);
}
/*
required_base (rqb), required_loop (rql)
base_loop (bl), repeat_loop (rl)
rqb + a0 * rql = bl + a1 * rl < minimize and store in required loop
a0 = (bl + a1 * rl - rqb) / rql
b0 * rql = b1 * rl < minimize and store in required loop
*/
}
print((req_base * buses[0].id));
}

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/*******************************************************************************
*
* Copyright (c) 2020 Gnarwhal
*
* -----------------------------------------------------------------------------
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files(the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*******************************************************************************/
#include <vector>
#include <map>
#include <string>
#include <bitset>
#include <iostream>
#include <fstream>
#include "../misc/types.hpp"
#include "../misc/print.hpp"
struct Op{ u8 op; u64 num1; u64 num2; };
auto set_memory(std::map<u64, u64> & map, u64 addr, const std::vector<bool> & maskX, usize index, u64 value) -> void {
while (++index < maskX.size() && !maskX[index]);
if (index == maskX.size()) {
map.insert_or_assign(addr, value);
} else {
set_memory(map, addr, maskX, index, value);
set_memory(map, addr ^ (u64(1) << (maskX.size() - index - 1)), maskX, index, value);
}
}
auto day14() -> void {
auto ops = std::vector<Op>();
{
auto line = std::string();
auto file = std::ifstream("inputs/day14.input");
while (getline(file, line)) {
if (line.find("mask") != std::string::npos) {
auto mask0 = u64(-1);
auto mask1 = u64( 0);
for (auto i = usize(7); i < line.size(); ++i) {
if (line[i] == '0') {
mask0 ^= (u64(1) << (42 - i));
} else if (line[i] == '1') {
mask1 ^= (u64(1) << (42 - i));
}
}
ops.push_back({ 0, mask0, mask1 });
} else {
auto value = line.find("=") + 2;
ops.push_back({
1,
u64(std::stoll(line.substr(4, line.find("]") - 4))),
u64(std::stoll(line.substr(value, line.size() - value)))
});
}
}
}
auto mask0 = u64(-1);
auto mask1 = u64( 0);
auto memory = std::map<u64, u64>();
for (auto op : ops) {
if (op.op == 0) {
mask0 = op.num1;
mask1 = op.num2;
} else {
memory.insert_or_assign(op.num1, (op.num2 & mask0) | mask1);
}
}
auto sum = u64(0);
for(auto mem : memory) {
sum += mem.second;
}
print(sum);
mask1 = u64(0);
memory = std::map<u64, u64>();
auto maskX = std::vector<bool>(36);
for (auto op : ops) {
if (op.op == 0) {
mask1 = op.num2;
for (auto i = usize(0); i < maskX.size(); ++i) {
auto bit = u64(1) << u64(35 - i);
maskX[i] = (op.num1 & bit) && !(op.num2 & bit);
}
} else {
set_memory(memory, op.num1 | mask1, maskX, -1, op.num2);
}
}
sum = u64(0);
for(auto mem : memory) {
sum += mem.second;
}
print(sum);
}