C + + Road Advanced--lca (trucking)

3287 Lorry Transport

2013 Noip National League Improvement Group

time limit: 1 sspace limit: 128000 KBtitle level: Diamonds DiamondTitle Description Description

A state-owned N-City, numbering from 1 to N, between cities there is m two-way road. Each road has a weight limit for the vehicle, which is referred to as the limit. There are now Q trucks transporting goods, and drivers want to know that each vehicle can carry more than the maximum amount of cargo in the case of a vehicle's limited weight.

Enter a description Input Description

The first line has two integer n,m separated by a space, representing a state-owned N-City and M-Road.
The next M-line is 3 integers x, y, Z, and every two integers separated by a space, indicating that from the city of X to the city of Y there is a road limited to Z. Note: x is not equal to Y, and there may be multiple roads between the two cities.
The next line has an integer q, which indicates that there is a Q truck that needs shipping.
Next Q line, two integers x, y per line, separated by a space, indicating that a lorry needs to transport goods from the X city to the Y city, note: x is not equal to Y.

Output description Output Description

The output is a total Q line, an integer per line, indicating the maximum load for each lorry. If the truck cannot reach its destination, output-1.

Sample input Sample Input

4 3
1 2 4
2 3 3
3 1 1
3
1 3
1 4
1 3

Sample output Sample Output

3
-1
3

Data range and Tips Data Size & Hint

For 30% data, 0 < n < 1,000,0 < m < 10,000,0 < Q < 1,000;
For 60% data, 0 < n < 1,000,0 < m < 50,000,0 < Q < 1,000;
For 100% data, 0 < n < 10,000,0 < m < 50,000,0 < Q < 30,000,0≤z≤100,000.

Exercises

Multiply LCA on a tree ...

Code:

1#include <cstdio>2#include <iostream>3#include <vector>4#include <algorithm>5 #defineMAXN 100106 7 using namespacestd;8  9vector<int>P[MAXN],C[MAXN];Ten  One structnode A    { -        intl,r,v; -}s[50010]; the     - structSS -     { -       intp;  +       intC;  -} f[maxn][ -]; +       A BOOLCMP (node A,node b) at      { -          returnA.v>B.V; -      } - intDEEP[MAXN],N,M,FA[MAXN],KG[MAXN]; -  - voidGetree (intKintd) in    { -deep[k]=D; tokg[k]=1; +       for(intI=1;(1<<i) <=deep[k];i++) -          { thef[k][i].p=f[f[k][i-1].p][i-1].P; *F[k][i].c=min (f[k][i-1].c,f[f[k][i-1].p][i-1].c); $              }    Panax Notoginseng      for(intI=0; I<p[k].size (); i++) -               if(!Deep[p[k][i]]) the                { +f[p[k][i]][0].p=K; Af[p[k][i]][0].c=C[k][i]; theGetree (p[k][i],d+1);  +                    }          -         }      $ intLcaintAintb) $    { -         if(deep[a]<deep[b]) swap (A, b); -           intt=deep[a]-Deep[b]; the           intans=0x7fffffff;  -              for(intI=0; i<= -; i++) Wuyi                 if((1<<i) &t) { theans=min (f[a][i].c,ans); -A=F[A][I].P; Wu             } -              for(intI= -; i>=0; i--) About               if(f[a][i].p!=F[B][I].P) $                  { -ans=min (f[b][i].c,ans); -ans=min (f[a][i].c,ans); -A=F[A][I].P; Ab=F[B][I].P;  +                   } the         if(a==b)returnans; -          Else returnMin (f[a][0].c,min (f[b][0].c,ans));  $             } the  the intFindintx) the    { the         if(fa[x]==x)returnx; -fa[x]=find (Fa[x]); in            returnFa[x]; the                }             the              About voidInit () the   { thescanf"%d%d",&n,&m);  the        for(intI=0; i<m;i++) +scanf"%d%d%d",&s[i].l,&s[i].r,&s[i].v);  -Sort (s+0, s+m,cmp);  the      for(intI=0; i<=n;i++)Bayifa[i]=i;  the    } the intMain () -    { - init (); the         for(intI=0; i<m;i++) the           { the                  intpp=find (S[I].L); the                  intqq=find (S[I].R); -                 if(pp!=QQ) the                    { thefa[pp]=QQ; the P[s[i].l].push_back (S[I].R);94 C[s[i].l].push_back (S[I].V); the P[s[i].r].push_back (S[I].L); the C[s[i].r].push_back (S[I].V); the                    }98           } About      for(intI=1; i<=n;i++) -        if(!kg[i]) getree (i,1); 101scanf"%d",&m); 102      for(intI=0; i<m;i++)103       {104             intx, y; thescanf"%d%d",&x,&y);106           if(Find (x)!=find (y)) printf ("-1\n");107            Elseprintf"%d\n", LCA (x, y)); 108             }      109      return 0;  the}

C + + Road Advanced--lca (trucking)