Day04

src/days/04/Day04.cpp

@@ -1,9 +1,58 @@
 #include "Day04.h"
 
 Result Day04::Task1() {
-	return Day::Task1();
+	int count = 0;
+	for (const RangePair &pair : parse()){
+		const Range range1 = pair.first;
+		const Range range2 = pair.second;
+
+		if (contains(range1, range2) || contains(range2, range1))
+			count++;
+	}
+
+	return to_string(count);
 }
 
 Result Day04::Task2() {
-	return Day::Task2();
-}
+	int count = 0;
+	for (const RangePair &pair : parse()){
+		const Range range1 = pair.first;
+		const Range range2 = pair.second;
+
+		if (overlap(range1, range2))
+			count++;
+	}
+
+	return to_string(count);
+}
+
+bool Day04::contains(Range outer, Range inner) {
+	return outer.first <= inner.first && outer.second >= inner.second;
+}
+
+bool Day04::overlap(Range r1, Range r2) {
+	bool R1LeftFromR2 = r1.first < r2.first && r1.second < r2.first;
+	bool R2LeftFromR1 = r2.first < r1.first && r2.second < r1.first;
+	return !(R1LeftFromR2 || R2LeftFromR1);
+}
+
+vector<RangePair> Day04::parse() const {
+	vector<RangePair> parsed;
+	for (const string &line : input){
+		const size_t comma = line.find(',');
+		const string range1 = line.substr(0, comma);
+		const string range2 = line.substr(comma + 1);
+
+		const size_t dash1 = range1.find('-');
+		const size_t dash2 = range2.find('-');
+
+		const int p1n1 = stoi(range1.substr(0, dash1));
+		const int p1n2 = stoi(range1.substr(dash1 + 1));
+
+		const int p2n1 = stoi(range2.substr(0, dash2));
+		const int p2n2 = stoi(range2.substr(dash2 + 1));
+
+		parsed.emplace_back(Range(p1n1, p1n2), Range(p2n1, p2n2));
+	}
+	return parsed;
+}

src/days/04/Day04.h

@@ -2,9 +2,17 @@
 
 #include "../../Day.h"
 
+typedef pair<int, int> Range;
+typedef pair<Range, Range> RangePair;
+
 class Day04 : public Day {
 protected:
 	Result Task1() override;
 
 	Result Task2() override;
+
+	vector<RangePair> parse() const;
+
+	static bool contains(Range, Range);
+	static bool overlap(Range, Range);
 };

src/util.h

@@ -9,4 +9,4 @@
 
 using std::stoi, std::to_string;
 using std::cout, std::endl;
-using std::string, std::vector, std::set;
+using std::string, std::vector, std::set, std::pair;