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86120c01a1
Author | SHA1 | Date |
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Benjamin Kraft | 86120c01a1 | 9 months ago |
Benjamin Kraft | 3c5d23433b | 9 months ago |
Benjamin Kraft | f8ce3f1ade | 9 months ago |
Benjamin Kraft | 85712eff12 | 9 months ago |
7 changed files with 161 additions and 10 deletions
@ -1,9 +1,84 @@ |
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#include "Day08.h" |
#include "Day08.h" |
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Result Day08::Task1() { |
Result Day08::Task1() { |
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return Day::Task1(); |
Map map = parseMap(); |
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vector<uint8_t> instructions = parseInstructions(); |
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uint64 steps = 0; |
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size_t instructionIndex = 0; |
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string node = "AAA"; |
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while (node != "ZZZ"){ |
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node = map[node][instructions[instructionIndex]]; |
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steps++; |
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instructionIndex = (++instructionIndex) % instructions.size(); |
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} |
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return to_string(steps); |
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} |
} |
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Result Day08::Task2() { |
Result Day08::Task2() { |
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return Day::Task2(); |
Map map = parseMap(); |
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} |
vector<uint8_t> instructions = parseInstructions(); |
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vector<string> nodes; |
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for (auto [node, path] : map) |
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if (node.ends_with('A')) |
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nodes.push_back(node); |
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vector<uint64> allSteps; |
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for (string &node : nodes){ |
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uint64 steps = 0; |
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size_t instructionIndex = 0; |
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while (!node.ends_with('Z')){ |
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node = map[node][instructions[instructionIndex]]; |
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steps++; |
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instructionIndex = (++instructionIndex) % instructions.size(); |
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} |
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allSteps.push_back(steps); |
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} |
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uint64 lcm = 1; |
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for (uint64 steps : allSteps) |
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lcm = LCM(lcm, steps); |
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return to_string(lcm); |
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} |
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Day08::Map Day08::parseMap() const { |
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Map map; |
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for (size_t i = 2; i < input.size(); i++){ |
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string line = input[i]; |
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string source = line.substr(0, 3); |
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string left = line.substr(7, 3); |
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string right = line.substr(12, 3); |
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map[source] = {left, right}; |
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} |
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return map; |
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} |
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vector<uint8_t> Day08::parseInstructions() const { |
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vector<uint8_t> instructions; |
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for (const char c : input[0]) |
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instructions.push_back(c == 'L' ? 0 : 1); |
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return instructions; |
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} |
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uint64 Day08::GCD(uint64 a, uint64 b) { |
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while (b != 0){ |
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uint64 t = b; |
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b = a % b; |
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a = t; |
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} |
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return a; |
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} |
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uint64 Day08::LCM(uint64 a, uint64 b) { |
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return a * b / GCD(a, b); |
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} |
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@ -1,9 +1,47 @@ |
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#include "Day09.h" |
#include "Day09.h" |
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Result Day09::Task1() { |
Result Day09::Task1() { |
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return Day::Task1(); |
int64 sum = 0; |
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for (auto &history : parseHistories()){ |
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vector<int64> tails = {history.back()}; |
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vector<int64> diff = history; |
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while (std::any_of(diff.begin(), diff.end(), [](int64 v){return v != 0;})){ |
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for (size_t i = 0; i < diff.size() - 1; i++) |
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diff[i] = diff[i + 1] - diff[i]; |
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diff.pop_back(); |
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tails.push_back(diff.back()); |
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} |
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sum += std::reduce(tails.begin(), tails.end(), 0, [](int64 a, int64 b){ return a + b; }); |
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} |
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return to_string(sum); |
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} |
} |
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Result Day09::Task2() { |
Result Day09::Task2() { |
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return Day::Task2(); |
int64 sum = 0; |
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} |
for (auto &history : parseHistories()){ |
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vector<int64> heads = {history.front()}; |
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vector<int64> diff = history; |
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while (std::any_of(diff.begin(), diff.end(), [](int64 v){return v != 0;})){ |
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for (size_t i = 0; i < diff.size() - 1; i++) |
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diff[i] = diff[i + 1] - diff[i]; |
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diff.pop_back(); |
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heads.push_back(diff.front()); |
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} |
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for (size_t i = 0; i < heads.size(); i++) |
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sum += heads[i] * (i % 2 == 0 ? 1 : -1); |
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} |
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return to_string(sum); |
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} |
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vector<vector<int64>> Day09::parseHistories() const { |
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vector<vector<int64>> histories; |
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for (const string &line : input) |
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histories.push_back(parseInts(line)); |
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return histories; |
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} |
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