添加字典树、并查集、Dijkstra算法

dijkstra.cpp

@@ -0,0 +1,35 @@
+class Solution {
+public:
+    int diskstra(vector<vector<int>>& edges, int n, int start, int end) {
+        vector<vector<int>> graph(n, vector<int>(n, INT_MAX / 2));
+        // === 建图 ===
+        for (auto& [from, to, dist]: edges) {
+            graph[from][to] = dist;
+        }
+
+        vector<int> distance(n, INT_MAX/2), visited(n, 0);
+        distance[start] = 0;
+        while (true) {
+            int next_node = -1;
+            for (int node = 0; node < n; node++) {
+                if (visited[node]) {
+                    continue;   // 不重复更新
+                }
+                if (next_node < 0 || distance[next_node] > distance[node]) {
+                    next_node = node;   // 寻找移动路径最小的节点
+                }
+            }
+
+            if (next_node < 0 || distance[next_node] == INT_MAX / 2) {
+                break;      // 找不到节点
+            }
+
+            visited[next_node] = 1;
+            for (int node = 0; node < n; node++) {
+                // 根据最近节点路径更新其余节点移动路径
+                distance[node] = min(distance[node], distance[next_node] + graph[next_node][node]);
+            }
+        }
+        return distance[end] == INT_MAX / 2 ? -1 : distance[end];
+    }
+};

trie_tree.cpp

@@ -0,0 +1,49 @@
+class Trie 
+{
+private:
+	vector<Trie*> m_children;
+	bool is_end;
+
+	Trie* searchPrefix(string prefix)
+	{
+		Trie* node = this;
+		for (char ch : prefix) {
+			if (node->m_children[ch - 'a'] == nullptr) {
+				return nullptr;
+			}
+			node = node->m_children[ch - 'a'];
+		}
+		return node;
+	}
+
+public:
+	Trie() :
+        m_children(26),
+        is_end(false)	
+	{
+
+	}
+
+	void insert(string word) 
+	{
+		Trie* node = this;
+		for (char ch : word) {
+			if (node->m_children[ch - 'a'] == nullptr) {
+				node->m_children[ch - 'a'] = new Trie;
+			}
+			node = node->m_children[ch - 'a'];
+		}
+		node->is_end = true;
+	}
+
+	bool search(string word) 
+	{
+		Trie* node = searchPrefix(word);
+		return node != nullptr && node->is_end;
+	}
+
+	bool startsWith(string prefix) 
+	{
+		return searchPrefix(prefix) != nullptr;
+	}
+};

union-find_sets.cpp

@@ -0,0 +1,36 @@
+class UnionFind {
+    vector<int> _pre;           // 代表元
+    vector<int> _rank;          // 集合的秩
+
+public:
+    UnionFind(int n) : _pre(n), _rank(n, 1), cc(n) {
+        // iota(fa.begin(), fa.end(), 0);
+        ranges::iota(fa, 0);
+    }
+
+    int find(int x) {
+        return _pre[x] == x ? x : _pre[x] = fint(_pre[x]);
+    }
+
+    bool same(int x, int y) {
+        return find(x) == find(y);
+    }
+
+    bool merge(int from, int to) {
+        int x = find(from), y = find(to);
+        if (x == y) {
+            return false;           //同一集合不做合并
+        }
+        if (_rank[x] < _rank[y]) {
+            _pre[x] = y;
+        }
+        else if (_rank[x] > _rank[y]) {
+            _pre[y] = x;
+        }
+        else {
+            _pre[x] = y;
+            _rank[y]++;
+        }
+        return true;
+    }
+};