BZOJ1196[HNOI2006] Highway construction problems

BZOJ1196[HNOI2006] Highway construction problems

Test instructions

Repair N-1 Road will be n points to connect, each point can be built a road can also be built a second-class highway, requires the first road must have K, requires the most cost of the road to spend the least.

Exercises

The first two minutes of the largest cost, and then decided: first in the premise of not producing the ring (with and check set maintenance) to make every road as far as possible to repair a road, if the last can not constitute a tree to consider the repair of the two-level highway.

Code:

1#include <cstdio>2#include <cstring>3#include <algorithm>4 #defineInc (I,J,K) for (int i=j;i<=k;i++)5 #defineMAXN 105006 using namespacestd;7 8 intn,k,m,u[maxn*2],v[maxn*2],c1[maxn*2],c2[maxn*2],mx,fa[maxn],cnt;9 intFindintx) {returnx==fa[x]?x:fa[x]=find (Fa[x]);}Ten BOOLCheckintLim) { OneInc (I,1, n) fa[i]=i; Cnt=0; AInc (I,1, m)if(c1[i]<=Lim) { -         intX=find (U[i]), Y=find (V[i]);if(x==y)Continue; Fa[y]=x; cnt++; -     } the     if(cnt<k)return 0; -Inc (I,1, m)if(c2[i]<=Lim) { -         intX=find (U[i]), Y=find (V[i]);if(x==y)Continue; Fa[y]=x; cnt++; -     } +     if(cnt<n-1)return 0;return 1; - } + intMain () { Ascanf"%d%d%d", &n,&k,&m); mx=0; atInc (I,1, M-1) scanf ("%d%d%d%d", &u[i],&v[i],&c1[i],&c2[i]), Mx=max (Mx,c1[i]), mx=Max (mx,c2[i]); -     intL=0, r=Mx,ans; -      while(l<=R) { -         intMid= (l+r) >>1; -         if(Check (mid)) ans=mid,r=mid-1;ElseL=mid+1; -     } inprintf"%d", ans);return 0; -}

20160531

BZOJ1196[HNOI2006] Highway construction problems