aoc

commit 4aebede600c180b51d0b6ded0e42ec8a4223283e
parent 5a23d15ff9bb69d9e9b52e543596e75af3b090f9
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date:   Tue,  3 Dec 2024 07:56:46 +0100

Added day 3 (bleah)

Diffstat:
A
2024/03/Makefile
 | 
24
++++++++++++++++++++++++
A
2024/03/b.out
 | 
0

A
2024/03/day03a.cpp
 | 
48
++++++++++++++++++++++++++++++++++++++++++++++++
A
2024/03/day03b.cpp
 | 
63
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
2024/learned.txt
 | 
2
++
M
2024/template.cpp
 | 
5
++++-

6 files changed, 141 insertions(+), 1 deletion(-)
diff --git a/2024/03/Makefile b/2024/03/Makefile
@@ -0,0 +1,24 @@
+CC=g++ -std=c++20 -g -Wall
+
+a:
+	${CC} -o a.out day03a.cpp
+
+b:
+	${CC} -o b.out day03b.cpp
+
+clean:
+	rm -f a b
+
+atest: a
+	./a.out
+
+btest: b
+	./b.out
+
+arun: a
+	./a.out < input
+
+brun: b
+	./b.out < input
+
+.PHONY: a b clean atest btest arun brun
diff --git a/2024/03/b.out b/2024/03/b.out
Binary files differ.
diff --git a/2024/03/day03a.cpp b/2024/03/day03a.cpp
@@ -0,0 +1,48 @@
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+int trymult(const string_view &s) {
+	if (s.substr(0, 4) != "mul(")
+		return 0;
+
+	auto t = s.substr(4, s.length()-4);
+
+	int x = 0, y = 0;
+	int i = 0;
+	for (; i < 3; i++)
+		if (t[i] >= '0' && t[i] <= '9')
+			x = (x*10) + t[i]-'0';
+		else break;
+	if (i == 0 || t[i] != ',')
+		return 0;
+	i++;
+	int j = 0;
+	for (; j < 3; j++)
+		if (t[i+j] >= '0' && t[i+j] <= '9')
+			y = (y*10) + t[i+j]-'0';
+		else break;
+	if (j == 0 || t[j+i] != ')')
+		return 0;
+	return x*y;
+}
+
+int mults(const string &line) {
+	int result = 0;
+	for (auto i = line.begin(); i != line.end(); i++)
+		result += trymult(string_view(i, line.end()));
+	return result;
+}
+
+int main() {
+	string line;
+	int result = 0;
+	while (cin >> line)
+		result += mults(line);
+	cout << result << endl;
+	return 0;
+}
diff --git a/2024/03/day03b.cpp b/2024/03/day03b.cpp
@@ -0,0 +1,63 @@
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+bool state = true;
+
+int trymult(const string_view &s) {
+	if (s.substr(0, 4) != "mul(")
+		return 0;
+
+	auto t = s.substr(4, s.length()-4);
+
+	int x = 0, y = 0;
+	int i = 0;
+	for (; i < 3; i++)
+		if (t[i] >= '0' && t[i] <= '9')
+			x = (x*10) + t[i]-'0';
+		else break;
+	if (i == 0 || t[i] != ',')
+		return 0;
+	i++;
+	int j = 0;
+	for (; j < 3; j++)
+		if (t[i+j] >= '0' && t[i+j] <= '9')
+			y = (y*10) + t[i+j]-'0';
+		else break;
+	if (j == 0 || t[j+i] != ')')
+		return 0;
+
+	return x*y;
+}
+
+bool trytogglestate(bool current_state, const string_view &s) {
+	if (s.substr(0, 4) == "do()")
+		return true;
+	if (s.substr(0, 7) == "don't()")
+		return false;
+	return current_state;
+}
+
+int mults(const string &line) {
+	int result = 0;
+	for (auto i = line.begin(); i != line.end(); i++) {
+		string_view s(i, line.end());
+		state = trytogglestate(state, s);
+		if (state)
+			result += trymult(s);
+	}
+	return result;
+}
+
+int main() {
+	string line;
+	int result = 0;
+	while (cin >> line)
+		result += mults(line);
+	cout << result << endl;
+	return 0;
+}
diff --git a/2024/learned.txt b/2024/learned.txt
@@ -1,3 +1,5 @@
 List of things I learned (or refreshed) with this year's AoC.
 
 * Day 1: std::count()
+* Day 2: std::sstream
+* Day 3: std::string_view
diff --git a/2024/template.cpp b/2024/template.cpp
@@ -1,6 +1,9 @@
+#include <algorithm>
 #include <iostream>
+#include <sstream>
+#include <string>
+#include <string_view>
 #include <vector>
-#include <algorithm>
 using namespace std;
 
 int main() {