78 lines
1.7 KiB
C++
78 lines
1.7 KiB
C++
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#include <fstream>
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#include <iostream>
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#include <string>
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#include <vector>
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using namespace std;
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vector<int> parse_line(string line) {
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int start = 0;
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vector<int> result;
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while (start < line.length()) {
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int end = line.find(" ", start);
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string word = line.substr(start, end - start);
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int n = stoi(word);
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result.push_back(n);
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start = end + 1;
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if (end == -1) {
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break;
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}
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}
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return result;
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}
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bool is_valid(vector<int> report) {
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int prev_diff = 0;
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for (int i = 1; i < report.size(); i++) {
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int diff = report[i] - report[i - 1];
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if (diff < -3 || diff == 0 || diff > 3) {
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return false;
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}
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// on the first iteration, we can't compare to the previous difference
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if (i == 1) {
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prev_diff = diff;
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continue;
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}
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if ((diff > 0 && prev_diff < 0) || (diff < 0 && prev_diff > 0)) {
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return false;
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}
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prev_diff = diff;
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}
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return true;
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}
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int main() {
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ifstream file("data/02.txt");
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string line;
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int count_part1 = 0;
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int count_part2 = 0;
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while (getline(file, line)) {
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auto report = parse_line(line);
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if (is_valid(report)) {
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count_part1++;
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count_part2++;
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}
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else {
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for (int i = 0; i < report.size(); i++) {
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int n = report[i];
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report.erase(report.begin() + i);
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if (is_valid(report)) {
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count_part2++;
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break;
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}
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report.insert(report.begin() + i, n);
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}
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}
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}
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cout << "Part 1: " << count_part1 << "\n";
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cout << "Part 2: " << count_part2 << "\n";
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}
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