1 files changed, 52 insertions, 0 deletions
diff --git a/2021/day01/day01.cpp b/2021/day01/day01.cpp
new file mode 100644
index 0000000..113f86d
--- /dev/null
+++ b/2021/day01/day01.cpp
@@ -0,0 +1,52 @@
+#include <iostream>
+#include <string>
+#include <vector> 
+#include <algorithm> 
+
+std::string read (char* name) {
+	FILE *f = fopen(name, "r");
+	char c = fgetc(f); std::string txt;
+	while (c != EOF) { txt += c; c = fgetc(f); }
+	fclose(f);
+	return txt;
+}
+
+std::vector<std::string> split (std::vector<std::string> vec, std::string name) {
+	auto token = name.find("\n");
+	if (token != std::string::npos) {
+		vec.push_back(name.substr(0, token));
+		return split(vec, name.substr(token+1));
+	} else if (name.size() > 1) { 
+		vec.push_back(name);
+	}
+	return vec;
+}
+
+int main (int argc, char* argv[]) {
+	if (argc < 2 && argc > 3) return 1;
+	std::string txt = read(argv[1]);
+
+	std::vector<std::string> vec;
+	vec = split(vec, txt);
+	std::vector<int> depths;
+	for (auto v : vec) {
+		depths.push_back(std::stoi(v));
+	}
+
+	int window = 1;
+	if (argc == 3) { window = atoi(argv[2]); }
+
+	int inc = 0;
+	for (std::size_t i=0; i<depths.size(); i++) {
+		if (i >= window) {
+			int sum0 = 0, sum1 = 0;
+			for (int j=0; j<window; j++) sum0 += depths[i-j-1];
+			for (int j=0; j<window; j++) sum1 += depths[i-j];
+			if (sum1 > sum0) inc ++;
+		}
+	}
+
+	std::cout << "The number of depth increases is " << inc << std::endl;
+
+	return 0;
+}