aoc24/01/main.cc

#include <fstream>
#include <iostream>
#include <vector>
using namespace std;

void parseFile(const char *path, vector<int> &list1, vector<int> &list2) {
  ifstream input_stream(path);
  int a;
  int b;

  while(input_stream >> a >> b) {
    list1.push_back(a);
    list2.push_back(b);
  }
}

void bubbleSort(vector<int> &list) {
  bool changed = false;

  for (int i = 0; i < list.size() - 1; i++) {
    int temp = list[i];
    if (list[i] > list[i + 1]) {
      int temp = list[i];
      list[i] = list[i + 1];
      list[i + 1] = temp;
      changed = true;
    }
  }

  if (changed) bubbleSort(list);
}

int count(int n, vector<int> list) {
  int cnt = 0;
  for (int i = 0; i < list.size(); i++) {
    if (list[i] == n) cnt++;
  }
  return cnt;
}

int main(int argc, char *argv[]) {
  vector<int> list1;
  vector<int> list2;

  // parse input
  parseFile("input", list1, list2);

  // sort lists
  bubbleSort(list1);
  bubbleSort(list2);

  // PART 1
  /// sum up differences
  int sum = 0;
  for (int i = 0; i < list1.size(); i++) {
    cout << list1[i] << "   " << list2[i] << endl;
    int difference = list1[i] - list2[i];
    if (difference > 0) {
      sum += difference;
    } else {
      sum -= difference;
    }
  }

  cout << "distance between lists is: " << sum << endl;

  // PART 2
  /// sum up similarities
  int sim_score = 0;
  for (int i = 0; i < list1.size(); i++) {
    sim_score += list1[i] * count(list1[i], list2);
  }

  cout << "similarity score is: " << sim_score << endl;

  return 0;
}