From 3c8331701f9f77c28847d678b935d5efb9a5d575 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Thu, 19 Dec 2024 07:21:47 +0100
Subject: Improved part 2 day 19 2024 with string_view

---
 2024/19/day19b-string.cpp | 54 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 2024/19/day19b-string.cpp

(limited to '2024/19/day19b-string.cpp')

diff --git a/2024/19/day19b-string.cpp b/2024/19/day19b-string.cpp
new file mode 100644
index 0000000..6f8b8f4
--- /dev/null
+++ b/2024/19/day19b-string.cpp
@@ -0,0 +1,54 @@
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <map>
+#include <queue>
+#include <ranges>
+#include <set>
+#include <sstream>
+#include <string>
+#include <string_view>
+#include <vector>
+using namespace std;
+
+vector<string> gettowels(const string& line) {
+	vector<string> ret;
+	int j = 0;
+	for (int i = 0; j != -1; i = j+2) {
+		j = line.find(",", i);
+		ret.push_back(line.substr(i, (j == -1 ? line.size() : j)-i));
+	}
+	return ret;
+}
+
+int64_t countpossible(const string& p, const vector<string>& towels, vector<int64_t>& mem) {
+	if (p.size() == 0)
+		return 1;
+	if (mem[p.size()] != -1)
+		return mem[p.size()];
+	int64_t ret = 0;
+	for (auto t : towels) {
+		if (t == p.substr(0, t.size()))
+			ret += countpossible(p.substr(
+			    t.size(), p.size() - t.size()), towels, mem);
+	}
+	return (mem[p.size()] = ret);
+}
+
+int main() {
+	string line;
+	getline(cin, line);
+	auto towels = gettowels(line);
+	getline(cin, line);
+	vector<string> patterns;
+	while (getline(cin, line))
+		patterns.push_back(line);
+	vector<int64_t> mem(1000);
+	int64_t count = 0;
+	for (auto p : patterns) {
+		for (auto& m : mem) m = -1;
+		count += countpossible(p, towels, mem);
+	}
+	cout << count << endl;
+	return 0;
+}
-- 
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