Pure C language: greedy Prim algorithm generation tree problem source sharing

#include <iostream.h>
#define MAX 100
#define MAXCOST 100000

int graph[MAX][MAX];

int Prim(int graph[MAX][MAX], int n)
{
 
 int lowcost[MAX];

 
 int mst[MAX];

 int i, j, min, minid, sum = 0;

 
 for (i = 1; i < n; i++)
 {
  
   lowcost[i] = graph[0][i];

  
  mst[i] = 0;
 }

 
 lowcost[0] = 0;

 
 for (i = 1; i < n; i++)
 {
  min = MAXCOST;
  minid = 0;

  
  for (j =1; j <n; j++)
  {
   
   if (lowcost[j] < min && lowcost[j] != 0)
   {
    min = lowcost[j];
    minid = j;
   }
  }
  
  cout<<" The starting point, ending point and weight of the generated edges are: "<< mst[minid]+1<<"  "<<minid+1<<"  "<<min<<endl;
  
  sum += min;

  
  lowcost[minid] = 0;

  
  for (j = 1; j < n; j++)
  {
   
   if (graph[minid][j] < lowcost[j])
   {
    
    lowcost[j] = graph[minid][j];

    
    mst[j] = minid;
   }
  }
 }
 
 return sum;
}

void main()
{
 int i, j,  m,n;
 int  cost;
  
 cout<<" Please enter the number of nodes in the figure: ";
 cin>>m;
 
 for (i = 0; i <m; i++)
 {
  for (j =i+1; j <m; j++)
  {
   cout<<" Please enter node "<<i+1<<" To the node "<<j+1<<" Edge weights, if boundless, input MAXCOST(100000):";
   cin>>n;
   graph[i][j] = n;
   graph[j][i] = n;
  }
  graph[i][i]=MAXCOST;
 }

 
 cost = Prim(graph, m);
 cout<<" The weight of the minimum spanning tree is: "<<cost<<endl;
}