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Mr. Kitayuta‘s Colorful Graph
Mr. Kitayuta has just bought an undirected graph consisting of n vertices and m edges. The vertices of the graph are numbered from 1 to n. Each edge, namely edge i, has a color ci, connecting vertex ai and bi.
Mr. Kitayuta wants you to process the following q queries.
In the i-th query, he gives you two integers — ui and vi.
Find the number of the colors that satisfy the following condition: the edges of that color connect vertex ui and vertex vi directly or indirectly.
The first line of the input contains space-separated two integers — n and m (2 ≤ n ≤ 100, 1 ≤ m ≤ 100), denoting the number of the vertices and the number of the edges, respectively.
The next m lines contain space-separated three integers — ai, bi (1 ≤ ai < bi ≤ n) and ci (1 ≤ ci ≤ m). Note that there can be multiple edges between two vertices. However, there are no multiple edges of the same color between two vertices, that is, if i ≠ j, (ai, bi, ci) ≠ (aj, bj, cj).
The next line contains a integer — q (1 ≤ q ≤ 100), denoting the number of the queries.
Then follows q lines, containing space-separated two integers — ui and vi (1 ≤ ui, vi ≤ n). It is guaranteed that ui ≠ vi.
For each query, print the answer in a separate line.
4 5
1 2 1
1 2 2
2 3 1
2 3 3
2 4 3
3
1 2
3 4
1 4
2
1
0
5 7
1 5 1
2 5 1
3 5 1
4 5 1
1 2 2
2 3 2
3 4 2
5
1 5
5 1
2 5
1 5
1 4
1
1
1
1
2
Let‘s consider the first sample.
The figure above shows the first sample.
并查集，暴力都可以过，大水题
1 #include <iostream> 2 using namespace std; 3 #define MAXN 110 4 int pa[110][110],ra[110][110]; 5 void init() 6 { 7 for(int i=0;i<MAXN;i++) 8 { 9 for(int j=0;j<MAXN;j++){ 10 pa[i][j]=j; 11 ra[i][j]=0; 12 } 13 } 14 } 15 int find(int x,int c){ 16 if(pa[c][x]!=x)pa[c][x]=find(pa[c][x],c); 17 return pa[c][x]; 18 } 19 int unite(int x,int y,int c){ 20 x=find(x,c); 21 y=find(y,c); 22 if(x==y)return 0; 23 if(ra[c][x]<ra[c][y]) 24 { 25 pa[c][x]=y; 26 }else{ 27 pa[c][y]=x; 28 if(ra[c][x]==ra[c][y])ra[c][x]++; 29 } 30 return 1; 31 } 32 bool same(int x,int y,int c){ 33 return find(x,c)==find(y,c); 34 } 35 36 int main() 37 { 38 ios::sync_with_stdio(false); 39 int n,m; 40 init(); 41 cin>>n>>m; 42 int u,v,c; 43 for(int i=0;i<m;i++){ 44 cin>>u>>v>>c; 45 u--,v--,c--; 46 unite(u,v,c); 47 } 48 int q; 49 cin>>q; 50 for(int i=0;i<q;i++){ 51 cin>>u>>v; 52 u--;v--; 53 int ans=0; 54 for(int i=0;i<m;i++) 55 { 56 if(same(u,v,i))ans++; 57 } 58 cout<<ans<<endl; 59 } 60 61 return 0; 62 }
codeforces 505B Mr. Kitayuta's Colorful Graph(水题)
原文：http://www.cnblogs.com/fraud/p/4338504.html
