void BronKerbosch(ll n, ll R, ll P, ll X) // initial call (0,(1LL<<n) - 1,0)
{
if (P == 0LL && X == 0LL)
{
ll t = 0;
vector <ll> v;
for (ll i = 0; i < n; i++)
if ((1ll << i) & R)
t ++, v.pb (i + 1);
if (t > res)
{
res = t;
clique = v;
}
res = max(res, t);
return;
}
ll u = 0;
while (!((1ll<<u) & (P|X)))
u ++;
for (ll v = 0; v < n; v++)
{
if (((1ll << v) & P) && !((1ll << v) & N[u]))
{
BronKerbosch(n, R | (1ll << v), P & N[v], X & N[v]);
P -= (1ll << v);
X |= (1ll << v);
}
}
}
// ne[u] is the neighbours of u
// v is the result, P = (1<<n) - 1
void BronKerbosch(ll R, ll P, ll X){
if ((P == 0LL) && (X == 0LL)) {v.push_back(R);return ;}
int u = 0;
for (; u < n; u ++) if ( (P|X) & (1LL << u) ) break;
for (int i = 0; i < n; i ++)
if ( (P&~ne[u]) & (1LL << i) ){
BronKerbosch(R | (1LL << i), P & ne[i], X & ne[i]);
P -= (1LL << i); X |= (1LL << i);
}
}
