Question

我有一个代码，可以找到最小的生成树权重。边被声明为int，但我需要将它们作为字符串。如何修改才能正常工作？如果将vector修改为字符串，则会在编译器中看到很多错误。请帮助我完成这段代码，我是编程新手。

#include<bits/stdc++.h>
using namespace std;
typedef pair<int, int> iPair;
struct Graph
{
    int Edges, Connections;
    vector< pair<int, iPair> > edges;
    Graph(int Edges, int Connections)
    {
        this->Edges = Edges;
        this->Connections = Connections;
    }
    void addEdge(int u, int v, int w)
    {
        edges.push_back({w, {u, v}});
    }
    int kruskalMST();
};
struct DisjointSets
{
    int *parent, *rnk;
    int n;
    DisjointSets(int n)
    {
        // Allocate memory
        this->n = n;
        parent = new int[n+1];
        rnk = new int[n+1];

        // Initially, all vertices are in
        // different sets and have rank 0.
        for (int i = 0; i <= n; i++)
        {
            rnk[i] = 0;

            //every element is parent of itself
            parent[i] = i;
        }
    }

    // Find the parent of a node 'u'
    // Path Compression
    int find(int u)
    {
        /* Make the parent of the nodes in the path
        from u--> parent[u] point to parent[u] */
        if (u != parent[u])
            parent[u] = find(parent[u]);
        return parent[u];
    }

    // Union by rank
    void merge(int x, int y)
    {
        x = find(x), y = find(y);

        /* Make tree with smaller height
        a subtree of the other tree */
        if (rnk[x] > rnk[y])
            parent[y] = x;
        else // If rnk[x] <= rnk[y]
            parent[x] = y;

        if (rnk[x] == rnk[y])
            rnk[y]++;
    }
};

/* Functions returns weight of the MST*/

int Graph::kruskalMST()
{
    int mst_wt = 0; // Initialize result

    // Sort edges in increasing order on basis of cost
    sort(edges.begin(), edges.end());

    // Create disjoint sets
    DisjointSets ds(Edges);

    // Iterate through all sorted edges
    vector< pair<int, iPair> >::iterator it;
    for (it=edges.begin(); it!=edges.end(); it++)
    {
        int u = it->second.first;
        int v = it->second.second;

        int set_u = ds.find(u);
        int set_v = ds.find(v);
        if (set_u != set_v)
        {
            cout << u << " - " << v << " = " << it->first << endl;
            mst_wt += it->first;
            ds.merge(set_u, set_v);
        }
    }    
    return mst_wt;
}
// Driver program to test above functions
int main()
{
    int from,to,weight,i;
    /* Let us create above shown weighted
    and unidrected graph */
    int Edges, Connections;
    cout<<"How many edges?:"; cin>>Edges;
    cout<<"How many connections?:"; cin>>Connections;
    Graph g(Edges, Connections);
    system("cls");
    // making above shown graph
    for(i=0;i<Connections;i++){
        cout<<endl;
            cout<<"From "; cin>>from;
            cout<<"To "; cin>>to;
            cout<<"Weight "; cin>>weight;
            g.addEdge(from,to,weight);
            system("cls");
    }
    cout << "Edges of MST are \n";
    int mst_wt = g.kruskalMST();

    cout << "\nWeight of MST is " << mst_wt;

    return 0;
}

Example of 9 edges and 14 connections. Minimal Weight = 37.

From    To  Weight
0       1    4
0       7    8
1       2    8
1       7   11
2       3    7
2       8    2
2       5    4
3       4    9
3       5   14
4       5   10
5       6    2
6       7    1
6       8    6
7       8    7

Min. Weight = 37

您可以输入您的值作为输入。

最小的生成树

0 个答案: