advent-of-code/2024/day01/part2.cc
2024-12-11 02:22:13 +00:00

22 lines
489 B
C++

#include <vector>
#include <unordered_map>
#include <iostream>
#include <ranges>
#include <cstdlib>
#include <cmath>
int main() {
std::vector<int> left_list;
std::unordered_map<int, int> right_list;
int left, right;
while (std::cin >> left >> right) {
left_list.emplace_back(left);
right_list[right]++;
}
int score = 0;
for(auto left_elem : left_list) {
score += left_elem * right_list[left_elem];
}
std::cout << score << std::endl;
return EXIT_SUCCESS;
}