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-rwxr-xr-x2021/day11/day11bin0 -> 68808 bytes
-rw-r--r--2021/day11/day11.cpp115
-rw-r--r--2021/day11/day11_input.txt10
-rw-r--r--2021/day11/day11_input_ez.txt10
-rw-r--r--2021/day11/makefile2
5 files changed, 137 insertions, 0 deletions
diff --git a/2021/day11/day11 b/2021/day11/day11
new file mode 100755
index 0000000..a39baa6
--- /dev/null
+++ b/2021/day11/day11
Binary files differ
diff --git a/2021/day11/day11.cpp b/2021/day11/day11.cpp
new file mode 100644
index 0000000..5a88b14
--- /dev/null
+++ b/2021/day11/day11.cpp
@@ -0,0 +1,115 @@
+#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;
+}
diff --git a/2021/day11/day11_input.txt b/2021/day11/day11_input.txt
new file mode 100644
index 0000000..d33c53b
--- /dev/null
+++ b/2021/day11/day11_input.txt
@@ -0,0 +1,10 @@
+6227618536
+2368158384
+5385414113
+4556757523
+6746486724
+4881323884
+4648263744
+4871332872
+4724128228
+4316512167
diff --git a/2021/day11/day11_input_ez.txt b/2021/day11/day11_input_ez.txt
new file mode 100644
index 0000000..03743f6
--- /dev/null
+++ b/2021/day11/day11_input_ez.txt
@@ -0,0 +1,10 @@
+5483143223
+2745854711
+5264556173
+6141336146
+6357385478
+4167524645
+2176841721
+6882881134
+4846848554
+5283751526
diff --git a/2021/day11/makefile b/2021/day11/makefile
new file mode 100644
index 0000000..7614d42
--- /dev/null
+++ b/2021/day11/makefile
@@ -0,0 +1,2 @@
+all day11.cpp:
+ g++ -std=c++20 -o day11 day11.cpp