BZOJ3697 the path of the person who picked the medicine

Point Division treatment ... What the hell! Konjac Konjac How to do so Mulberry heart%>_<%

Orz Hzwer

Konjac Konjac to add something Hzwer didn't say:

(1) for negative plant weights set to-1, positive is set to +1

(2) The last paragraph is about how to use the new subtree's f[] value to find ans and update g[]

1 /**************************************************************2 problem:36973 User:rausen4 language:c++5 result:accepted6 time:1752 Ms7 memory:15924 KB8 ****************************************************************/9  Ten#include <cstdio> One#include <algorithm> A   - using namespacestd; - Const intN =100005; the   - structEdge { -     intNext, to, V; - Edge () {} +Edgeint_n,int_t,int_v): Next (_n), to (_t), V (_v) {} -} e[n <<1]; +    A intfirst[n], tot; at    - structTree_node { -     intsz, DEP, DIS; -     BOOLVis; - } Tr[n]; -    in intN, K; - intCnt[n <<1]; to Long LongF[n <<1][2], G[n <<1][2], ans; + intRoot, Maxsz; - intmx_dep, MX; the   *InlineintRead () { $     intx =0;Panax Notoginseng     CharCH =GetChar (); -      while(Ch <'0'||'9'<ch) theCH =GetChar (); +      while('0'<= CH && Ch <='9') { Ax = x *Ten+ CH-'0'; theCH =GetChar (); +     } -     returnx; $ } $   - voidAdd_edges (intXintYintz) { -E[++tot] = Edge (first[x], y, z), first[x] =tot; theE[++tot] = Edge (First[y], x, z), first[y] =tot; - }Wuyi    the voidDfsintPintFaintSZ) { -     intX, y, Maxsz =0; WuTR[P].SZ =1; -      for(x = first[p]; x; x =e[x].next) About         if((y = e[x].to)! = FA &&!Tr[y].vis) { $ dfs (Y, p, sz); -Tr[p].sz + =Tr[y].sz; -Maxsz =Max (Maxsz, TR[Y].SZ); -         } AMaxsz = Max (Maxsz, Sz-tr[p].sz); +     if(Maxsz <Maxsz) theRoot = p, Maxsz =Maxsz; - } $    the intGet_root (intPintSZ) { theMaxsz = N <<1; theDFS (p,0, SZ); the     returnRoot; - } in   the voidDfs (intPintFA) { the     intx, y; AboutMX_DEP =Max (MX_DEP, TR[P].DEP); the     if(Cnt[tr[p].dis]) ++f[tr[p].dis][1]; the     Else++f[tr[p].dis][0]; the++Cnt[tr[p].dis]; +      for(x = first[p]; x; x =e[x].next) -         if((y = e[x].to)! = FA &&!Tr[y].vis) { theTR[Y].DEP = TR[P].DEP +1, Tr[y].dis = Tr[p].dis +e[x].v;Bayi Dfs (y, p); the         } the--Cnt[tr[p].dis]; - } -   the voidCalintp) { the     intx, Y, J; theMX =0, g[n][0] =1; the      for(x = first[p]; x; x =e[x].next) -         if(!tr[y =E[x].to].vis) { theTr[y].dis = n + e[x].v, TR[Y].DEP =1, MX_DEP =1; the Dfs (y, p); theMX =max (MX, MX_DEP);94Ans + = (g[n][0] -1) * f[n][0]; the              for(j =-mx_dep; J <= Mx_dep; + +j) theAns + = g[n-j][1] * f[n + j][1] + g[n-j][0] * f[n + j][1] + g[n-j][1] * f[n + j][0];  the              for(j = n-mx_dep; J <= N + mx_dep; + +)j) {98g[j][0] + = f[j][0], g[j][1] + = f[j][1]; Aboutf[j][0] = f[j][1] =0; -             }101         }102      for(j = n-mx; J <= n + mx; + +)j)103g[j][0] = g[j][1] =0;104 } the  106 voidWorkintPintSZ) {107     intRoot =get_root (P, SZ), x, y;108Tr[root].vis =1;109 cal (root); the      for(x = first[root]; x; x =e[x].next)111         if(!tr[y =E[x].to].vis) the Work (y, tr[y].sz);113 } the   the intMain () { the     intI, x, Y, Z;117n =read ();118      for(i =1; I < n; ++i) {119x = Read (), y = read (), z =read (); -Add_edges (x, Y, z?)1: -1);121     }122Work1, n);123printf"%lld\n", ans);124     return 0; the}

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(In fact, I think ...) Point Division to achieve 1600ms is the limit, rank the front of the two should use a special skill ♂ skillfully )

BZOJ3697 the path of the person who picked the medicine