# Prims algorithm for minimum spanning tree

```#include <iostream.h>
#include <conio.h>
#define ROW 7
#define COL 7
#define infi 5000  //infi for infinity

class prims
{
int graph[ROW][COL],nodes;
public:
prims();
void createGraph();
void primsAlgo();
};

prims :: prims(){
for(int i=0;i<ROW;i++)
for(int j=0;j<COL;j++)
graph[i][j]=0;
}

void prims :: createGraph(){
int i,j;
cout<<\"Enter Total Nodes : \";
cin>>nodes;
cout<<\"\\n\\nEnter Adjacency Matrix : \\n\";
for(i=0;i<nodes;i++)
for(j=0;j<nodes;j++)
cin>>graph[i][j];

//Assign infinity to all graph[i][j] where weight is 0.
for(i=0;i<nodes;i++){
for(j=0;j<nodes;j++){
if(graph[i][j]==0)
graph[i][j]=infi;
}
}
}

void prims :: primsAlgo(){
int selected[ROW],i,j,ne; //ne for no. of edges
int false=0,true=1,min,x,y;

for(i=0;i<nodes;i++)
selected[i]=false;

selected[0]=true;
ne=0;

while(ne < nodes-1){
min=infi;

for(i=0;i<nodes;i++)
{
if(selected[i]==true){
for(j=0;j<nodes;j++){
if(selected[j]==false){
if(min > graph[i][j])
{
min=graph[i][j];
x=i;
y=j;
}
}
}
}
}
selected[y]=true;
cout<<\"\\n\"<<x+1<<\" --> \"<<y+1;
ne=ne+1;
}
}

void main(){
prims MST;
clrscr();
cout<<\"\\nPrims Algorithm to find Minimum Spanning Tree\\n\";
MST.createGraph();
MST.primsAlgo();
getch();
}
```

Didn't find what you were looking for? Find more on Prims algorithm for minimum spanning tree