利用set在C++中实现Dijkstra算法

#include <iostream>
#include <set>
#include <vector>
#include <limits>

using namespace std;

const int INF = numeric_limits<int>::max();

// 定义图的邻接表表示
typedef pair<int, int> Edge; // <目标节点, 权重>
typedef vector<vector<Edge>> Graph;

vector<int> dijkstra(const Graph& graph, int source) {
    int n = graph.size();
    vector<int> dist(n, INF); // 存储源节点到各个节点的最短距离
    set<pair<int, int>> pq; // 存储待处理的节点，按照距离值排序

    dist[source] = 0;
    pq.insert({0, source});

    while (!pq.empty()) {
        int u = pq.begin()->second;
        pq.erase(pq.begin());

        for (const auto& edge : graph[u]) {
            int v = edge.first;
            int weight = edge.second;

            if (dist[u] + weight < dist[v]) {
                pq.erase({dist[v], v});
                dist[v] = dist[u] + weight;
                pq.insert({dist[v], v});
            }
        }
    }

    return dist;
}

int main() {
    int n = 5; // 节点数
    int source = 0; // 源节点

    Graph graph(n);

    // 添加边
    graph[0].push_back({1, 10});
    graph[0].push_back({2, 3});
    graph[1].push_back({2, 1});
    graph[1].push_back({3, 2});
    graph[2].push_back({1, 4});
    graph[2].push_back({3, 8});
    graph[2].push_back({4, 2});
    graph[3].push_back({4, 7});
    graph[4].push_back({3, 9});

    vector<int> shortestDist = dijkstra(graph, source);

    // 输出最短路径
    for (int i = 0; i < n; i++) {
        cout << "Shortest distance from node " << source << " to node " << i << ": " << shortestDist[i] << endl;
    }

    return 0;
}