prims

  #include <stdio.h>

#include <limits.h>

#define V_MAX 100

int minKey(int key[], int mstSet[], int V) {

    int min = INT_MAX, min_index;

    for (int v = 0; v < V; v++)

        if (mstSet[v] == 0 && key[v] < min)

            min = key[v], min_index = v;

    return min_index;

}

void printMST(int parent[], int V, int graph[V_MAX][V_MAX]) {

    printf("Edge Weight\n");

    for (int i = 1; i < V; i++)

        printf("%d - %d %d \n", parent[i], i, graph[i][parent[i]]);

}

void primMST(int graph[][V_MAX], int V) {

    int parent[V_MAX];

    int key[V_MAX];

    int mstSet[V_MAX];

    for (int i = 0; i < V; i++) {

        key[i] = INT_MAX;

        mstSet[i] = 0;

    }

    key[0] = 0;

    parent[0] = -1;

    for (int count = 0; count < V - 1; count++) {

        int u = minKey(key, mstSet, V);

        mstSet[u] = 1;

        for (int v = 0; v < V; v++)

            if (graph[u][v] && mstSet[v] == 0 && graph[u][v] < key[v])

                parent[v] = u, key[v] = graph[u][v];

    }

    printMST(parent, V, graph);

}

int main() {

    int V, E;

    printf("Enter the number of vertices and edges: ");

    scanf("%d %d", &V, &E);

    int graph[V_MAX][V_MAX];

    for (int i = 0; i < V; i++) {

        for (int j = 0; j < V; j++) {

            graph[i][j] = 0;

        }

    }

    printf("Enter the source vertex, destination vertex, and weight for each edge:\n");

    for (int i = 0; i < E; i++) {

        int source, dest, weight;

        scanf("%d %d %d", &source, &dest, &weight);

        graph[source][dest] = weight;

        graph[dest][source] = weight;

    }

    primMST(graph, V);

    return 0;

}