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#include <iostream>
#include <fstream>
#include <vector>
#include <string>
class State {
public: State() { iter = 0; booms = 0; }
int size;
std::vector<int> light;
int xytoi (int x, int y) { return x+y*size; }
int itox (int i) { return i % size; }
int itoy (int i) { return i / size; }
int iter;
int booms;
bool oob (int x, int y) {
if (x < 0 || x >= size) return true;
if (y < 0 || y >= size) return true;
return false;
}
bool calm () {
for (std::size_t i=0; i<light.size(); i++) {
if (light[i] > 9) return false;
}
return true;
}
void propagate (int x, int y) {
for (int i=-1; i<2; i++) {
for (int j=-1; j<2; j++) {
if (!oob(x+i, y+j)) {
light[xytoi(x+i, y+j)]++;
}
}
}
}
void solve () {
for (int y=0; y<size; y++) {
for (int x=0; x<size; x++) {
int i = xytoi(x, y);
if (light[i] > 9) {
propagate(x, y);
booms ++;
light[i] = -10000000;
solve();
return;
}
}
}
if (!calm()) solve();
}
void step () {
for (int y=0; y<size; y++) {
for (int x=0; x<size; x++) {
int i = xytoi(x, y);
light[i] ++;
}
}
solve();
for (std::size_t i=0; i<light.size(); i++) {
if (light[i] < 0) light[i] = 0;
}
iter ++;
}
void show () {
std::cout << "iter: " << iter << std::endl;
for (int y=0; y<size; y++) {
for (int x=0; x<size; x++) {
std::cout << light[xytoi(x, y)];
}
std::cout << std::endl;
}
std::cout << std::endl;
}
};
int main (int argc, char * argv[]) {
std::string line;
std::vector<std::string> lines;
std::ifstream f { argv[1] };
do {
std::getline(f, line);
if (line.size() > 1) lines.push_back(line);
} while (!f.eof());
State state;
for (auto l : lines) {
state.size = 0;
for (char c : l) {
state.light.push_back(std::stoi(std::string { c }));
state.size ++;
}
}
state.show();
int last = 0;
int iters = argc > 2 ? atoi(argv[2]) : 100;
for (int i=0; i<iters; i++) {
state.step();
state.show();
if (state.booms - last == 100) {
break;
}
last = state.booms;
}
std::cout << "flashes: " << state.booms << std::endl;
return 0;
}
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