add: 0015

more/0015.cpp

@@ -0,0 +1,39 @@
+#include <vector>
+#include <unordered_set>
+
+struct tripletHash {
+	std::size_t operator()(const std::vector<int>& v) const {
+		return (size_t(v[0]) << 36) ^ (size_t(v[1]) << 18) ^ size_t(v[2]);
+	}
+};
+
+class Solution {
+public:
+	static std::vector<std::vector<int>> threeSum(std::vector<int>& nums) {
+		std::vector<std::vector<int>> ret;
+		std::sort(nums.begin(), nums.end());
+		std::unordered_set<int> s(nums.begin(), nums.end());
+		for (auto it = std::upper_bound(nums.begin(), nums.end(), 0); it != nums.end(); ++it)
+			for (auto it2 = std::next(it); it2 != nums.end(); ++it2)
+				if (s.count(-(*it + *it2)))
+					ret.push_back({-(*it + *it2), *it, *it2});
+		for (auto it = nums.begin(), lim = std::lower_bound(nums.begin(), nums.end(), 0); it != lim; ++it)
+			for (auto it2 = std::next(it); it2 != lim; ++it2)
+				if (s.count(-(*it + *it2)))
+					ret.push_back({*it, *it2, -(*it + *it2)});
+		if (s.count(0))
+			for (auto it = std::upper_bound(nums.begin(), nums.end(), 0); it != nums.end(); ++it)
+				if (s.count(-*it))
+					ret.push_back({-*it, 0, *it});
+		if (3 <= std::distance(std::lower_bound(nums.begin(), nums.end(), 0), std::upper_bound(nums.begin(), nums.end(), 0)))
+			ret.push_back({0, 0, 0});
+		std::unordered_set<std::vector<int>, tripletHash> retSet(ret.begin(), ret.end());
+		return {retSet.begin(), retSet.end()};
+	}
+};
+
+int main() {
+	std::vector<int> args = {1,1,-2};
+	auto ret = Solution::threeSum(args);
+	return 0;
+}

more/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(more)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(more 0005.cpp)
+ADD_EXECUTABLE(more 0015.cpp)