2023 day 14

2023/14/main-1.cpp

@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	vector<string> lines;
+
+	string line;
+	while (getline(cin, line) && !line.empty()) {
+		lines.push_back(line);
+	}
+
+	int ret = 0;
+	for (unsigned int r = 0; r < lines.size(); r++) {
+		for (unsigned int c = 0; c < lines[r].size(); c++) {
+			if (lines[r][c] == 'O') {
+				lines[r][c] = '.';
+				int rr = r;
+				while (rr != 0 && lines[rr - 1][c] == '.') {
+					rr--;
+				}
+				lines[rr][c] = 'O';
+				ret += lines.size() - rr;
+			}
+		}
+	}
+
+	cout << ret << '\n';
+}

2023/14/main-2.cpp

@@ -0,0 +1,101 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+vector<string> lines;
+
+const int numtimes = 1000000000;
+
+inline vector<vector<unsigned int>> hashlines() {
+	vector<vector<unsigned int>> ret;
+	for (auto& row : lines) {
+		vector<unsigned int> retl;
+		for (unsigned int c = 0; c < row.size(); c++) {
+			if (row[c] == 'O') {
+				retl.push_back(c);
+			}
+		}
+		ret.push_back(retl);
+	}
+	return ret;
+}
+
+int main() {
+	ios::sync_with_stdio(0);
+	cin.tie(0);
+
+	string line;
+	while (getline(cin, line) && !line.empty()) {
+		lines.push_back(line);
+	}
+
+	vector<vector<vector<unsigned int>>> all;
+
+	for (unsigned int i = 0; i < numtimes; i++) {
+		for (unsigned int r = 0; r < lines.size(); r++) {
+			for (unsigned int c = 0; c < lines[r].size(); c++) {
+				if (lines[r][c] == 'O') {
+					lines[r][c] = '.';
+					unsigned int rr = r;
+					while (rr != 0 && lines[rr - 1][c] == '.') {
+						rr--;
+					}
+					lines[rr][c] = 'O';
+				}
+			}
+		}
+		for (auto& row : lines) {
+			for (unsigned int c = 0; c < row.size(); c++) {
+				if (row[c] == 'O') {
+					row[c] = '.';
+					unsigned int cc = c;
+					while (cc != 0 && row[cc - 1] == '.') {
+						cc--;
+					}
+					row[cc] = 'O';
+				}
+			}
+		}
+		for (unsigned int r = lines.size() - 1; (int)r >= 0; r--) {
+			for (unsigned int c = 0; c < lines[r].size(); c++) {
+				if (lines[r][c] == 'O') {
+					lines[r][c] = '.';
+					unsigned int rr = r;
+					while (rr != lines.size() - 1 && lines[rr + 1][c] == '.') {
+						rr++;
+					}
+					lines[rr][c] = 'O';
+				}
+			}
+		}
+		for (auto& row : lines) {
+			for (unsigned int c = row.size() - 1; (int)c >= 0; c--) {
+				if (row[c] == 'O') {
+					row[c] = '.';
+					unsigned int cc = c;
+					while (cc != row.size() - 1 && row[cc + 1] == '.') {
+						cc++;
+					}
+					row[cc] = 'O';
+				}
+			}
+		}
+		const auto& hashed = hashlines();
+		for (unsigned int j = 0; j < i; j++) {
+			if (all[j] == hashed) {
+				unsigned int diff = i - j;
+				all.push_back(all[(numtimes - j - 1) % diff + j]);
+				goto mainexit;
+			}
+		}
+		all.push_back(hashed);
+	}
+ mainexit:
+
+	auto& lastver = all.back();
+	int ret = 0;
+	for (unsigned int r = 0; r < lastver.size(); r++) {
+		ret += (lastver.size() - r) * lastver[r].size();
+	}
+
+	cout << ret << '\n';
+}