add: 2A.cpp

1 files changed, 41 insertions, 0 deletions

diff --git a/2024/2A.cpp b/2024/2A.cpp
new file mode 100644
index 0000000..c8a5a19
--- /dev/null
+++ b/2024/2A.cpp
@@ -0,0 +1,41 @@
+#include <bits/stdc++.h>
+#include "readfile.hpp"
+
+
+int main(int argc, char const *argv[])
+{
+	int res = 0;
+	std::vector<std::string> file = readfile("2A.in");
+	if (file.empty())
+		return 1;
+
+	for (const auto &line : file) {
+		std::istringstream iss(line);
+		int n;
+		bool safe = true;
+		int prev = -1;
+		bool increasing = false, decreasing = false;
+		// put to vector and pair of two
+		while (iss >> n) {
+			if (prev == -1) {
+				prev = n;
+				continue;
+			}
+			if (prev < n)
+				increasing = true;
+			else if (prev > n)
+				decreasing = true;
+			if (std::abs(prev - n) > 3 || prev == n || (n > prev && decreasing || n < prev && increasing || increasing && decreasing || !increasing && !decreasing)) {
+				safe = false;
+				break;
+			}
+			prev = n;
+		}
+		if (safe) {
+			res++;
+		}
+	}
+
+	// print
+	std::cout << res << std::endl;
+}
\ No newline at end of file