# Prim’s Minimum Spanning Tree (MST)

//Library to access INT_MAX variable

#include <limits.h>

//Library to create set

#include <stdbool.h>

#include <stdio.h>

#define Vertices 5

//A utility function for finding the vertex with the lowest key value from a set of vertices that isn’t included in MST.

int Least_Key(int key[], bool Min_Span_Tree[])

int least = INT_MAX, min_index;

for (int v = 0; v < Vertices; v++)

if (Min_Span_Tree[v] == false && key[v] < least)

least = key[v], min_index = v;

return min_index;

//Function to print created MST

int print_Prims_MST(int parent[], int graph[Vertices][Vertices])

printf(“Edge \tWeight\n”);

for (int i = 1; i < Vertices; i++)

printf(“%d – %d \t%d \n”, parent[i], i, graph[i][parent[i]]);

//Function to generate MST

void prims_MST(int graph[Vertices][Vertices])

int parent[Vertices];

int key[Vertices];

bool Min_Span_Tree[Vertices];

for (int i = 0; i < Vertices; i++)

key[i] = INT_MAX, Min_Span_Tree[i] = false;

key = 0;

parent = -1;

for (int count = 0; count < Vertices – 1; count++)

int u = Least_Key(key, Min_Span_Tree);

Min_Span_Tree[u] = true;

for (int v = 0; v < Vertices; v++)

if (graph[u][v] && Min_Span_Tree[v] == false && graph[u][v] < key[v])

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

printf(“Created Spanning Tree for Given Graph is: \n”);

printf(“\n”);

print_Prims_MST(parent, graph);

int main()

int graph[Vertices][Vertices] = 0, 3, 0, 6, 0 ,

3, 0, 4, 8, 5 ,

0, 4, 0, 0, 7 ,

6, 8, 0, 0, 11 ,

0, 5, 7, 11, 0 ;

prims_MST(graph);

return 0;