Advent of Code 2021 Day 22: https://www.reddit.com/r/adventofcode/comments/rlxhmg/2021_day_22_solutions/hpizerm/

22.cpp

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

struct Op
{
	int xm, xM, ym, yM, zm, zM, sw;
};

int cube[101][101][101] = {};

int main()
{
	vector<Op> vop;
	vector<int> xs, ys, zs;
	string s;
	while(getline(cin, s))
	{
		Op op;
		op.sw = s[1] == 'n' ? 1 : 0;
		size_t p = s.find('=');
		op.xm = stoi(s.substr(p+1));
		xs.push_back(op.xm);
		p = s.find('.', p);
		op.xM = stoi(s.substr(p+2));
		xs.push_back(op.xM+1);
		p = s.find('=', p);
		op.ym = stoi(s.substr(p+1));
		ys.push_back(op.ym);
		p = s.find('.', p);
		op.yM = stoi(s.substr(p+2));
		ys.push_back(op.yM+1);
		p = s.find('=', p);
		op.zm = stoi(s.substr(p+1));
		zs.push_back(op.zm);
		p = s.find('.', p);
		op.zM = stoi(s.substr(p+2));
		zs.push_back(op.zM+1);
		vop.push_back(op);
	}
	
	// part 1
	for(auto& op : vop)
	{
		if(op.xm < -50 || op.xM > 50 || op.ym < -50 || op.yM > 50 || op.zm < -50 || op.zM > 50)
			continue;
		for(int x = op.xm; x <= op.xM; x++)
			for(int y = op.ym; y <= op.yM; y++)
				for(int z = op.zm; z <= op.zM; z++)
					cube[x+50][y+50][z+50] = op.sw;
	}
	
	int count = 0;
	for(int x = 0; x <= 100; x++)
		for(int y = 0; y <= 100; y++)
			for(int z = 0; z <= 100; z++)
				count += cube[x][y][z];
	cout << count << endl;
	
	// part 2
	sort(xs.begin(), xs.end());
	sort(ys.begin(), ys.end());
	sort(zs.begin(), zs.end());
	
	vector<vector<vector<int>>> dcube;
	dcube.resize(xs.size(), vector<vector<int>>(ys.size(), vector<int>(zs.size())));
	for(auto& op : vop)
	{
		int xm = lower_bound(xs.begin(), xs.end(), op.xm) - xs.begin(),
			xM = lower_bound(xs.begin(), xs.end(), op.xM+1) - xs.begin(),
			ym = lower_bound(ys.begin(), ys.end(), op.ym) - ys.begin(),
			yM = lower_bound(ys.begin(), ys.end(), op.yM+1) - ys.begin(),
			zm = lower_bound(zs.begin(), zs.end(), op.zm) - zs.begin(),
			zM = lower_bound(zs.begin(), zs.end(), op.zM+1) - zs.begin();
		for(int xi = xm; xi < xM; xi++)
			for(int yi = ym; yi < yM; yi++)
				for(int zi = zm; zi < zM; zi++)
					dcube[xi][yi][zi] = op.sw;
	}
	
	int64_t allCount = 0;
	for(int xi = 0; xi < xs.size() - 1; xi++)
		for(int yi = 0; yi < ys.size() - 1; yi++)
			for(int zi = 0; zi < zs.size() - 1; zi++)
				if(dcube[xi][yi][zi])
					allCount += (int64_t)(xs[xi+1] - xs[xi]) * (ys[yi+1] - ys[yi]) * (zs[zi+1] - zs[zi]);
	cout << allCount << endl;
	
	return 0;
}