import heapqdef prim(graph, start): n = len(graph) visited = [False] * n distance = [float('inf')] * n distance[start] = 0 heap = [(0, start)] while heap: _, u = heapq.heappop(heap) if visited[u]: continue visited[u] = True for v, w in graph[u]: if not visited[v] and w < distance[v]: distance[v] = w heapq.heappush(heap, (w, v)) return sum(distance)def min_distance_sum(graph): n = len(graph) min_distance = float('inf') for i in range(n): distance_sum = prim(graph, i) min_distance = min(min_distance, distance_sum) return min_distancegraph = [ [(1, 2), (2, 1)], [(0, 2), (2, 3), (3, 1)], [(0, 1), (1, 3), (3, 1)], [(1, 1), (2, 1)]]print(min_distance_sum(graph)) # 输出：4把这段代码转换成c++

以下是将 Python 代码转换为 C++ 的版本：

#include <iostream>
#include <vector>
#include <queue>
#include <limits>

using namespace std;

typedef pair<int, int> pii;

int prim(vector<vector<pii>>& graph, int start) {
    int n = graph.size();
    vector<bool> visited(n, false);
    vector<int> distance(n, numeric_limits<int>::max());
    distance[start] = 0;
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    pq.push({0, start});
    while (!pq.empty()) {
        int u = pq.top().second;
        pq.pop();
        if (visited[u]) {
            continue;
        }
        visited[u] = true;
        for (auto [v, w] : graph[u]) {
            if (!visited[v] && w < distance[v]) {
                distance[v] = w;
                pq.push({w, v});
            }
        }
    }
    int sum = 0;
    for (int i = 0; i < n; i++) {
        sum += distance[i];
    }
    return sum;
}

int min_distance_sum(vector<vector<pii>>& graph) {
    int n = graph.size();
    int min_distance = numeric_limits<int>::max();
    for (int i = 0; i < n; i++) {
        int distance_sum = prim(graph, i);
        min_distance = min(min_distance, distance_sum);
    }
    return min_distance;
}

int main() {
    vector<vector<pii>> graph = {
        {{1, 2}, {2, 1}},
        {{0, 2}, {2, 3}, {3, 1}},
        {{0, 1}, {1, 3}, {3, 1}},
        {{1, 1}, {2, 1}}
    };
    cout << min_distance_sum(graph) << endl;  // 输出：4
    return 0;
}