HDU 2473 Junk-Mail Filter delete point and query set

HDU 2473 Junk-Mail Filter delete point and query set

To delete a vertex and query a set, replace the previous vertex with a new vertex mark .. Y.

#include 
 
  #include 
  
   #include #include 
   
    #include 
    
     #include 
     #include 
      
       #include 
       
        #include 
        
         #include 
         
          using namespace std;#define mod 1000000007#define ll int#define N 100101ll r[1100010], f[1100010], a[N], top;ll n, m;ll find(ll x){return x==f[x]?x:f[x] = find(f[x]);}void Union(ll x, ll y){ ll fx = find(x), fy = find(y); if(fx==fy) return; if(r[fx]>r[fy]) swap(fx,fy); f[fx] = fy; r[fy] += r[fx];}void Del(ll x){find(a[x]);a[x] = top;r[top] = 1;f[top] = top;top++;}void init(){ for(ll i = 0; i < n; i++) f[i] = a[i] = i, r[i] = 1;top = n;}set
          
           s;int main(){int i, j, u, v, Cas = 1;while(scanf("%d %d",&n,&m), n+m){init();while(m--){char c[10]; scanf("%s %d",c,&u);if(c[0]=='M'){scanf("%d",&v);Union(a[u], a[v]);}else Del(u);}s.clear();for(i = 0; i < n; i++) for(i = 0; i < n; i++)s.insert(find(a[i]));printf("Case #%d: %d\n", Cas++, s.size());}return 0;}