BZOJ3624 [Apio2008] Free Road

Is the idea of greed ... Take 1 and then fetch 0 of the edges.

Once you have verified that you are not satisfied with the requirements, do the spanning tree again.

Anyway Kruskal is O (m) without pressure 2333

1 /**************************************************************2 problem:36243 User:rausen4 language:c++5 result:accepted6 time:60 Ms7 memory:16416 KB8 ****************************************************************/9  Ten#include <cstdio> One   A using namespacestd; - Const intN =20005; - Const intM =100005; the Const intMaxLen =15000010; -   - structEdges { -     intx, y; + edges () {} -Edgesint_x,int_y): X (_x), Y (_y) {} + }e[m]; A   at intN, M, K, CNT; - intFa[n]; - BOOLVis[m]; -   - CharBuf[maxlen]; - intLen, left; in   -InlineintRead () { to     intx =0; +      while(Buf[left] <'0'||'9'< Buf[left]) + +Left ; -      while('0'<= Buf[left] && Buf[left] <='9') thex = x *Ten+ buf[left++]-'0'; *     returnx; $ }Panax Notoginseng     - intLen =0, pr[ the]; theInlinevoidPrintintx) { +     if(X <0) Putchar ('-'), x =-x; A      while(x) thePr[++len] = x%Ten, x/=Ten; +     if(!len) Putchar ('0'); -      while(len) $Putchar (pr[len--] +'0'); $ } -   -   the intFIND_FA (intx) { -     returnFA[X] = = x? X:FA[X] =Find_fa (fa[x]);Wuyi } the   - intMain () { Wu     intI, X, Y, F, L, R, FA1, FA2; -Len = Fread (buf,1, MaxLen, stdin); AboutBuf[len] =' '; $n = Read (), M = Read (), k =read (); -      for(i =1, L =0, R = m +1; I <= m; ++i) { -x = Read (), y = Read (), F =read (); -         if(f) E[++l] =edges (x, y); A         ElseE[--R] =edges (x, y); +     } the       -      for(i =1; I <= N; ++i) Fa[i] =i; $      for(i =1; I <= m; ++i) the         if((FA1 = Find_fa (e[i].x))! = (FA2 =Find_fa (E[I].Y))) { theFA[FA1] =FA2; the             if(I >L) theVis[i] =1, cnt + =1; -         } in     if(CNT >k) { thePuts"No solution"); the         return 0; About     } the       the      for(i =1; I <= N; ++i) Fa[i] =i; the      for(i = R; I <= m; + +)i) +         if(Vis[i]) Fa[find_fa (e[i].x)] =Find_fa (E[I].Y); -      for(i = R; I <= m; + +)i) the         if(!vis[i] && cnt < K && (fa1 = Find_fa (e[i].x))! = (FA2 =Find_fa (E[I].Y))) {BayiFA[FA1] = FA2, vis[i] =1; the++CNT; the         } -     if(CNT! =k) { -Puts"No solution"); the         return 0; the     } the       the      for(i =1; I <= L; ++i) -         if((FA1 = Find_fa (e[i].x))! = (FA2 =Find_fa (E[I].Y))) theFA[FA1] = FA2, vis[i] =1; the      for(i =1; I <= m; ++i) the         if(Vis[i]) {94Print (e[i].x), Putchar (' '); thePrint (E[I].Y), Putchar (' '); thePrint (i <= L), Putchar ('\ n'); the         }98}

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(P.S. With IO plug cheated a rank.1, liquid! ）

BZOJ3624 [Apio2008] Free Road