add: 220426 [cpp]

cpp/2204/220426.cpp

@@ -0,0 +1,72 @@
+#include <algorithm>
+#include <vector>
+#include <queue>
+#include <unordered_set>
+
+class DisjointSet {
+private:
+	std::vector<int> parent;
+
+public:
+	explicit DisjointSet(int n) {
+		parent.reserve(n);
+		for (int i = 0; i < n; ++i)
+			parent.push_back(i);
+	}
+
+	int Find(int x) {
+		return (parent[x] == x) ? x : (parent[x] = Find(parent[x]));
+	}
+
+	void Union(int x, int y) {
+		auto xR = Find(x), yR = Find(y);
+		if (xR != yR)
+			parent[xR] = yR;
+	}
+
+};
+
+struct TupleCmp {
+	bool operator()(const std::tuple<int, int, int>& x, const std::tuple<int, int, int>& y) const {
+		return std::get<2>(x) > std::get<2>(y);
+	}
+};
+
+/**
+ * 1584. Min Cost to Connect All Points
+ * You are given an array points representing integer coordinates of some points on a 2D-plane, where points[i] = [xi, yi].
+ * The cost of connecting two points [xi, yi] and [xj, yj] is the manhattan distance between them: |xi - xj| + |yi - yj|, where |val| denotes the absolute value of val.
+ * Return the minimum cost to make all points connected. All points are connected if there is exactly one simple path between any two points.
+ */
+
+class Solution {
+public:
+	static int minCostConnectPoints(std::vector<std::vector<int>>& points) {
+		int n = points.size();
+		if (n <= 1)
+			return 0;
+
+		std::vector<std::tuple<int, int, int>> edgePairs;
+		for (int i = 0; i < n; ++i)
+			for (int j = i + 1; j < n; ++j)
+				edgePairs.emplace_back(i, j, std::abs(points[i][0] - points[j][0]) + std::abs(points[i][1] - points[j][1]));
+
+		std::priority_queue<std::tuple<int, int, int>, std::vector<std::tuple<int, int, int>>, TupleCmp> q(edgePairs.begin(), edgePairs.end());
+		DisjointSet s(n);
+
+		int ans = 0, cnt = 0;
+		while (cnt < n - 1) {
+			auto cur = q.top();
+			q.pop();
+			auto i = std::get<0>(cur);
+			auto j = std::get<1>(cur);
+			if (s.Find(i) != s.Find(j)) {
+				s.Union(i, j);
+				ans += std::get<2>(cur);
+				++cnt;
+			}
+		}
+
+		return ans;
+	}
+};

cpp/2204/CMakeLists.txt

@@ -3,4 +3,4 @@ PROJECT(2204)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2204 220425-CN.cpp)
+ADD_EXECUTABLE(2204 220426.cpp)