cf949c Data Center Maintenance (build + strong Unicom component)

Test instructions

There are n information centers, and the I Information Center is to be maintained during the TI hours, and during maintenance, the message cannot be obtained.

Each user's data is backed up by two copies, and the data for the I user is placed in Information Center C (i,1) and C (i,2).

Now to pick a small collection of information centers, so that the maintenance time of this set is delayed one hours, still can ensure that each user's data at any time can be obtained.

n≤100000

For each pair of C (i,1), C (i,2), if you adjust C (i,1) and C (i,2) after the maintenance time conflict, then the Edge (C (i,1), C (i,2)) for C (i,2), C (i,1) and the strong connected component, the set is the smallest SCC with a degree of 0 after the contraction point

1#include <iostream>2#include <cstring>3#include <cstdio>4#include <algorithm>5#include <cmath>6 using namespacestd;7 Const intn=500100;8 intCnt,head[n];9 intDfn[n],low[n],stack[n],vis[n],w[n],c[n],num,tot,top;Ten intN,m,h,t[n],ans,a[n],b[n],deg[n]; One structedge{ A     intto,nxt; - }e[n]; - voidAddintUintv) { thecnt++; -e[cnt].nxt=Head[u]; -e[cnt].to=v; -head[u]=CNT; + } - voidTarjan (intu) { +dfn[u]=low[u]=++tot; Astack[++top]=u; atvis[u]=1; -      for(intI=head[u];i;i=e[i].nxt) { -         intv=e[i].to; -         if(dfn[v]==0){ - Tarjan (v); -low[u]=min (low[u],low[v]); in         } -         Else if(Vis[v]) low[u]=min (low[u],dfn[v]); to     } +     if(low[u]==Dfn[u]) { -         intx; thenum++; *          Do{ $x=stack[top--];Panax Notoginsengc[x]=num+N; -w[num+n]++; theAdd (num+n,x); +vis[x]=0; A} while(x!=u); the     } + } - intMain () { $scanf"%d%d%d",&n,&m,&h); $      for(intI=1; i<=n;i++){ -scanf"%d",&t[i]); -     } the      for(intI=1; i<=m;i++){ -scanf"%d%d",&a[i],&b[i]);Wuyi         if(t[a[i]]+1==t[b[i]]| | (t[a[i]]==h-1&&t[b[i]]==0) Add (A[i],b[i]); the         if(t[b[i]]+1==t[a[i]]| | (t[b[i]]==h-1&&t[a[i]]==0) Add (B[i],a[i]); -     } Wu      for(intI=1; i<=n;i++){ -         if(dfn[i]==0) Tarjan (i); About     } $      for(intI=1; i<=m;i++){ -         if(C[a[i]]==c[b[i]])Continue; -         if(t[a[i]]+1==t[b[i]]| | (t[a[i]]==h-1&&t[b[i]]==0)) deg[c[a[i]]]++; -         if(t[b[i]]+1==t[a[i]]| | (t[b[i]]==h-1&&t[a[i]]==0)) deg[c[b[i]]]++; A     } +     intminn=9999999; the      for(inti=n+1; i<=n+num;i++){ -         if(deg[i]==0&&minn>W[i]) { $minn=W[i]; theans=i; the         } the     } theprintf"%d\n", W[ans]); -      for(intI=head[ans];i;i=e[i].nxt) { in         intv=e[i].to; theprintf"%d", v); the     }  About     return 0; the}

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cf949c Data Center Maintenance (build + strong Unicom component)