Update main.cpp

14/main.cpp

@@ -3,3 +3,69 @@
 Вариант 1. С помощью алгоритма Прима.
 */
 
+#include <iostream>
+#include <algorithm>
+#include <queue>
+#include <unordered_map>
+#include <assert.h>
+#include <list>
+#include <vector>
+#define INT_MAX 2147483647
+
+using std::vector;
+using std::queue;
+using std::cout;
+using std::pair;
+class Graph {
+public:
+    Graph(int v): v(v) { adj.assign(v, {}); };
+    void add_edge( int u, int v, int w );
+    int MST() const;
+private:
+    const int v;
+    vector<vector <pair<int, int> > > adj;
+};
+void Graph::add_edge( int u, int v, int w ) {
+    adj[u-1].push_back( {v-1, w} );
+    adj[v-1].push_back( {u-1, w} );
+}
+struct Less {
+    const bool operator()( pair <int, int>& left, pair <int, int>& right ) const {
+        return left.second > right.second;
+    };
+};
+int Graph::MST () const {
+    if ( adj.size() == 0 ) { return 0; }
+    int result = 0;
+    std::priority_queue< pair <int, int>, vector< pair<int,int> >, Less> positions_queue;
+    vector<bool> visited( adj.size(), false );
+//Начинаем обход с вершины 0
+    positions_queue.push( { 0, 0 } );
+    while (!positions_queue.empty()) {
+        pair<int, int> current = positions_queue.top();
+        positions_queue.pop();
+        if ( visited[current.first] ) { continue; }
+        visited[current.first] = true;
+        result += current.second;
+        for (auto sibling : adj[current.first]) {
+            if ( !visited[sibling.first] ) {
+                positions_queue.push( sibling );
+            }
+        }
+    }
+    return result;
+}
+
+int main() {
+    int v_, n;
+    std::cin >> v_ >> n;
+    Graph g(v_);
+    for ( int i = 0; i < n; ++i ) {
+        int u, v, w;
+        std::cin >> u >> v >> w;
+        g.add_edge( u, v, w );
+    }
+    cout << g.MST() << std::endl;
+    return 0;
+}
+