使用 Kruskal 算法查找最小生成树的错误

我编写将顶点添加到图形中的代码并更新边缘的权重，然后找到最小生成树。我认为我已经做到了，但似乎有一些错误，但我无法找到它。系统使用 Valgrind 并在 MST 的调用中指示"大小为 4 的无效写入"和"大小为 4 的无效读取"，但我认为它工作正常。瓦尔格林德的整个错误是 https://docs.google.com/document/d/1_AhOdDkyZGNTBVHspyGtnSQoU1tYkm0nVA5UABmKljI/edit?usp=sharing

以下代码由 like 调用

CreateNewGraph();
AddEdge(1, 2, 10);
AddEdge(2, 4, 10);
AddEdge(1, 3, 100);
AddEdge(3, 4, 10);
GetMST(mst_edges);

结果将是 (1,2( (2,4( (3,4(。

并致电

UpdateEdge(1, 3, 0.1);
GetMST(mst_edges);

结果将是 (1,2( (1,3( (2,4(。

它被发送到一个系统执行，它将像上面一样被调用，但在上面的很多时间周期中。

#include <vector>
#include <utility>
#include <algorithm>
using namespace std;
namespace HOMEWORK{
    class Edge{
        public:
            Edge(unsigned int, unsigned int, double);
            unsigned int u;
            unsigned int v;
            double w;
        friend bool operator<(const Edge& a, const Edge& b){
         return a.w < b.w;
        }
    };
    Edge::Edge(unsigned int source = 0, unsigned int destination = 0, double weight = 0.0){
        u = source;
        v = destination;
        w = weight;
    }
    vector<Edge> graph(0);
    vector<int> parent(0);
    int findset(int x){
        if(x != parent[x])parent[x] = findset(parent[x]);
        return parent[x];
    }
    void CreateNewGraph(){
        graph.clear();
        parent.clear();
    }
    void AddEdge(unsigned int u, unsigned int v, double w){
        graph.push_back(Edge(u,v,w));
    }
    void UpdateEdge(unsigned int u, unsigned int v, double w){
        for(int i = 0; i < graph.size(); i ++){
            if(graph[i].u == u && graph[i].v == v)graph[i] = Edge(u,v,w);
        }
    }
    void GetMST(vector<pair<unsigned int, unsigned int> >& mst_edges){
        mst_edges.clear();
        parent.clear();
        int e = graph.size();
        for(int i = 0; i <= e + 1; i ++)parent.push_back(i);
        stable_sort(graph.begin(), graph.end());
        for(int i = 0; i < e; i ++){
            //cout << graph[i].u << ":" << graph[i].v << ":" << graph[i].w << ":" << parent[i + 1] << endl;
            int pu = findset(graph[i].u);
            int pv = findset(graph[i].v);
            if(pu != pv){
                parent[pu] = parent[pv];
                mst_edges.push_back(make_pair(graph[i].u, graph[i].v));
            }
        }
    }
    void Init(){
    }
    void Cleanup(){
    }
}