void solve_case()
{
int i,j,k;
/* 1. construct edges for all pairs of stones */
k = 0;
for (i=0; i<n; i++)
for (j=i+1; j<n; j++)
{
e[k].u = i;
e[k].v = j;
e[k].w = SQR(x[i]-x[j])+SQR(y[i]-y[j]);
k++;
}
/* 2. sort edges by length */
qsort(e,k,sizeof(edge),edgecmp);
/* 3. generate a forest of one tree per stone */
for (i=0; i<n; i++)
make_set(i);
/* 4. while Freddy and Fiona are not in the same tree, add an edge to the forest */
for (i=0; !same_set(0,1); i++)
union_sets(e[i].u,e[i].v);
/* 5. output */
printf("Scenario #%d\n",++scenario);
printf("Frog Distance = %.3f\n\n",sqrt((double)(e[i-1].w)));
}
void merge(int x, int y){
if (!same_set(x, y)){
int u = find(x); int v = find(y);
if (rank[u] > rank[v]) {
p[v] = u;
set_size[u] += set_size[v];
} else {
p[u] = v;
set_size[v] += set_size[u];
if (rank[u] == rank[v])
++rank[v];
}
--disj_sets;
}
}
void union_sets (int x, int y)
{
if (!same_set(x,y)) link(find_set(x),find_set(y));
}