Something like this:
int node[]={11,11,0,11,11,11,11,11};
int used[]={0,0,0,0,0,0,0,0,0,0};
int nodeCon[8];
void generatePrims(){
int cNode = 3;
int next, min_now;
for(int i=0; i<8; ++i) {
used[cNode] = 1;
min_now = MAX_INT;
for(int i=1;i<=8;i++){
if(!used[i]){
if(node[i] > graph[cNode][i]){
node[i] = graph[cNode][i];
nodeCon[i]= cNode;
}
if(node[i] < min_now) {
min_now = node[i];
next = i;
}
}
}
cNode = next;
}
};
Also worth noting: it will be faster if instead of array 'used' you will use a list of unused vertices.