82 lines
2.5 KiB
C++
82 lines
2.5 KiB
C++
#include <iostream>
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#include <fstream>
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#include <vector>
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#include <map>
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// Advent of Code 2023, Day 3 Part 2
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using namespace std;
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int main() {
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ifstream input("input.txt");
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vector<string> lines;
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for (string line; getline(input, line);) {
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lines.push_back("." + line + ".");
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}
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map<string, vector<int>> gears;
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int sum = 0;
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for (int i = 0; i < lines.size(); i++) {
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string beforeLine = i > 0 ? lines[i - 1] : "";
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string currentLine = lines[i];
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string nextLine = i > lines.size() ? "" : lines[i + 1];
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bool buildMode = false;
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string numberString;
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for (int charIndex = 0; charIndex < currentLine.size(); charIndex++) {
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char current = currentLine[charIndex];
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if (isdigit(current)) {
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buildMode = true;
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numberString.push_back(current);
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continue;
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}
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if (buildMode) {
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cout << "checking " << numberString;
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int start = charIndex - numberString.size() - 1;
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for (int numSize = start > 0 ? start : 0; numSize <= charIndex; numSize++) {
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char currentBelow = i > 0 ? beforeLine[numSize] : '.';
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char currentNext = i > lines.size() - 2 && numSize > nextLine.size() ? '.' : nextLine[numSize];
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bool isInCurrent = (numSize > currentLine.size() ? '.' : currentLine[numSize]) == '*';
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bool isInBelow = currentBelow == '*';
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bool isInNext = currentNext == '*';
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if (isInCurrent || isInBelow || isInNext) {
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int line = isInBelow ? i - 1 : isInNext ? i + 1 : i;
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string gearId = to_string(line) + "-" + to_string(numSize);
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gears[gearId].push_back(stoi(numberString));
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cout << " - adding as " << to_string(line) + "-" + to_string(numSize);
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break;
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}
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}
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cout << "\n";
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numberString = "";
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buildMode = false;
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}
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}
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}
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for (const auto &item: gears) {
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int temp = 1;
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cout << "SEQUENCE " << item.first << endl;
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if (item.second.size() != 2) continue;
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for (const auto &gear: item.second) {
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temp *= gear;
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cout << " + " << gear;
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}
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cout << "\n";
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sum += temp;
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}
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cout << "Sum: " << sum;
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} |