prims

#include <iostream.h>
#include <conio.h>
#include <limits.h>

#define V 5 // Number of vertices in the graph

int minKey(int key[], bool mstSet[]) {
int min = INT_MAX, min_index;

for (int v = 0; v < V; v++)
    if (mstSet[v] == false && key[v] < min)
        min = key[v], min_index = v;

return min_index;

}

void printMST(int parent[], int n, int graph[V][V]) {
cout << "Edge \tWeight\n";
for (int i = 1; i < V; i++)
cout << parent[i] << " - " << i << " \t" << graph[i][parent[i]] << " \n";
}

void primMST(int graph[V][V]) {
int parent[V]; // Array to store the constructed MST
int key[V]; // Key values used to pick minimum weight edge in cut
bool mstSet[V]; // To represent set of vertices not yet included in MST

for (int i = 0; i < V; i++)
    key[i] = INT_MAX, mstSet[i] = false;

key[0] = 0;     // Make key 0 so that this vertex is picked as first vertex
parent[0] = -1; // First node is always root of MST

for (int count = 0; count < V - 1; count++) {
    int u = minKey(key, mstSet);

    mstSet[u] = true;

    for (int v = 0; v < V; v++)
        if (graph[u][v] && mstSet[v] == false && graph[u][v] < key[v])
            parent[v] = u, key[v] = graph[u][v];
}

printMST(parent, V, graph);

}

void main() {
clrscr();

int graph[V][V] = {
    {0, 2, 0, 6, 0},
    {2, 0, 3, 8, 5},
    {0, 3, 0, 0, 7},
    {6, 8, 0, 0, 9},
    {0, 5, 7, 9, 0}
};

primMST(graph);

getch();

}