int main() { //freopen("/home/qitaishui/code/in.txt","r",stdin); int n,m=0,u,v,ans; scanf("%d",&n); for(int i = 0; i < n;i++) p[i].input(); for(int i = 0; i < n; i++) for(int j = i+1; j < n; j++) seg[m++] = Node(i,j,(p[i].x-p[j].x)*(p[i].x-p[j].x)+(p[i].y-p[j].y)*(p[i].y-p[j].y)); sort(seg,seg+m); //cout<<"*\n"; for(int i = 0; i < m; i++) { u = seg[i].u,v = seg[i].v; tmp = bit[u]&bit[v]; //cout<<u<<endl; if(tmp.any()) { ans = seg[i].d; break; } bit[u].set(v); bit[v].set(u); } //cout<<ans<<endl; printf("%.10f\n",sqrt(1.0*ans)/2); return 0; }
bitset<BITS> HamiltonMatrix::removeParticle(int n, bitset<BITS> state) { // Vacuum state if (state.any() == false) return state; bitset<BITS> a; a.set(n - 1); bitset<BITS> comp = a & state; if (comp.count() == true) { state.set(n - 1, 0); } else { state.reset(); } return state; }