bzoj3624: [Apio2008] Free Road

Specific title: https://vjudge.net/problem/HYSBZ-3624

Description

A kingdom has n cities and M-strips of road, some of which are cobblestone roads and some are cement road. Now the king has to choose as few roads as possible for free, and make every two cities a free route. The king intends to keep just the K-Cobblestone road. Will the king be able to do all these requirements if it can output the path of the two cities and the type of road, otherwise "no solution".

HINT
N <= 20000
M <= 100000

Analysis
If it succeeds, it must be the smallest spanning tree.
The practice is to deform the Kruskal.
Connect all the cement road and then join the cobblestone Road to get the cobblestone paths that must be used (if more than K Direct no solution), and then press Kruskal to connect the cobblestone path to the K bar (if not to direct no solution), and then continue to follow the Kruskal connection Cement Road.

Spit Groove: At the end of the text must be changed (WA has nearly 20 rounds).

Code

1#include <iostream>2#include <cstdio>3#include <cctype>4 using namespacestd;5 Const intMAXN =20020;6 Const intMAXM =100010;7 intN, M, K, Fat[maxn], cnt0, cnt1, num;8 BOOLCHS[MAXM];9 structEdgeTen { One     intu, V, c; A } E[MAXM]; -  -InlineintReadint () the { -     Charc =GetChar (); -      while(!isdigit (c)) C =GetChar (); -     intx =0; +      while(IsDigit (c)) -     { +x = x *Ten+ C-'0'; Ac =GetChar (); at     } -     returnx; - } -  - intUnionset (intu) - { in     returnFat[u] = = u? U:fat[u] =Unionset (Fat[u]); - } to  + intMain () - { then =readint (); *m =readint (); $K =readint ();Panax Notoginseng      for(inti =1; I <= N; ++i) Fat[i] =i; -      for(inti =1; I <= m; ++i) the     { +E[I].U =readint (); AE[I].V =readint (); theE[I].C =readint (); +     } -      for(inti =1; I <= m; ++i) $     { $         if(E[I].C = =1) -         { -             intR1 =Unionset (e[i].u); the             intr2 =Unionset (E[I].V); -             if(R1! =R2)Wuyi             { theFAT[R1] =R2; -++cnt1; Wu             } -         } About     } $      for(inti =1; I <= m; ++i) -     { -         if(E[I].C = =0) -         { A             intR1 =Unionset (e[i].u); +             intr2 =Unionset (E[I].V); the             if(R1! =R2) -             { $Chs[i] =true; theFAT[R1] =R2; the++cnt0; the             } the         } -     } in     if(cnt0 + Cnt1! = N-1|| Cnt0 >k) the     { theprintf"No solution\n"); About         return 0; the     } the      for(inti =1; I <= N; ++i) Fat[i] =i; thecnt0 = Cnt1 =0; +      for(inti =1; I <= m; ++i) -     { the         if(Chs[i])Bayi         { the             intR1 =Unionset (e[i].u); the             intr2 =Unionset (E[I].V); -             if(R1! =R2) -             { theFAT[R1] =R2; the++cnt0; the             } the         } -     } the      for(inti =1; I <= m; ++i) the     { the         if(E[I].C = =0&& Cnt0 <k)94         { the             intR1 =Unionset (e[i].u); the             intr2 =Unionset (E[I].V); the             if(R1! =R2)98             { AboutChs[i] =true; -FAT[R1] =R2;101++cnt0;102             }103         }104     } the     if(Cnt0! =k)106     {107printf"No solution\n");108         return 0;109     } the      for(inti =1; I <= m; ++i)111     { the         if(E[I].C = =1)113         { the             intR1 =Unionset (e[i].u); the             intr2 =Unionset (E[I].V); the             if(R1! =R2)117             {118Chs[i] =true;119FAT[R1] =R2; -             }121         }122     }123      for(inti =1; I <= m; ++i)124         if(Chs[i]) theprintf"%d%d%d\n", E[i].u, E[I].V, e[i].c);126     return 0;127}

bzoj3624: [Apio2008] Free Road