advent-of-code/2023/11/main-1.cpp

#include <bits/stdc++.h>
using namespace std;

int main(int argc, char* argv[]) {
	ios::sync_with_stdio(0);
	cin.tie(0);

	bool dontwork = argc == 2 && !strcmp(argv[1], "DONTWORK");

	vector<string> lines;
	string line;
	while (getline(cin, line) && !line.empty()) {
		lines.push_back(line);
		if (dontwork)
			goto next1;
		for (char c : line) {
			if (c != '.') {
				goto next1;
			}
		}
		lines.push_back(line);
	next1:;
	}

	if (dontwork)
		goto next3;
	for (unsigned int col = 0; col < lines[0].size(); col++) {
		for (auto& r : lines) {
			if (r[col] != '.') {
				goto next2;
			}
		}
		for (auto& l : lines) {
			l.insert(l.begin() + col, '.');
		}
		col++;
	next2:;
	}
next3:

	vector<pair<int, int>> gs;
	for (unsigned int row = 0; row < lines.size(); row++) {
		for (unsigned int col = 0; col < lines[row].size(); col++) {
			if (lines[row][col] == '#') {
				gs.push_back(make_pair(row, col));
			}
		}
	}

	int ret = 0;
	for (unsigned int i = 0; i < gs.size() - 1; i++) {
		auto& gi = gs[i];
		for (unsigned int j = i + 1; j < gs.size(); j++) {
			auto& gj = gs[j];
			ret += abs(gi.first - gj.first) + abs(gi.second - gj.second);
		}
	}

	cout << ret << '\n';
}