Codeforces Round #286 (Div. 2) B 并查集

B. Mr. Kitayuta's Colorful Graph
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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.

Input

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.

Output

For each query, print the answer in a separate line.

Examples
Input
4 5
1 2 1
1 2 2
2 3 1
2 3 3
2 4 3
3
1 2
3 4
1 4
Output
2
1
0
Input
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
Output
1
1
1
1
2
qNote

Let's consider the first sample.

The figure above shows the first sample.
  • Vertex 1 and vertex 2 are connected by color 1 and 2.
  • Vertex 3 and vertex 4 are connected by color 3.
  • Vertex 1 and vertex 4 are not connected by any single color.

题意:n个点的图 m条边 两个点间可以有多条边 但是两点间相同颜色的边只能有一条  q个查询 判断 u-v间可以通过多少种颜色的边联通 

题解:并查集处理

 1 #pragma comment(linker, "/STACK:102400000,102400000")
 2 #include <cstdio>
 3 #include <iostream>
 4 #include <cstdlib>
 5 #include <cstring>
 6 #include <algorithm>
 7 #include <cmath>
 8 #include <cctype>
 9 #include <map>
10 #include <set>
11 #include <queue>
12 #include <bitset>
13 #include <string>
14 #include <complex>
15 #define ll __int64
16 #define mod 1000000007
17 using namespace std;
18 int n,m;
19 int fa[105][105];
20 int find(int root,int c)
21 {
22     if(fa[c][root]==root)
23         return root;
24     else
25         return fa[c][root]=find(fa[c][root],c);
26 }
27 void unio(int a,int b,int c)
28 {
29     int aa=find(a,c);
30     int bb=find(b,c);
31     if(aa!=bb)
32         fa[c][aa]=bb;
33 }
34 int main()
35 {
36     scanf("%d %d",&n,&m);
37     for(int i=1;i<=m;i++)
38         for(int j=1;j<=n;j++)
39           fa[i][j]=j;
40     int a,b,c;
41     for(int i=1;i<=m;i++)
42     {
43         scanf("%d %d %d",&a,&b,&c);
44         unio(a,b,c);
45     }
46     int q;
47     scanf("%d",&q);
48     for(int i=1;i<=q;i++)
49     {
50         scanf("%d %d",&a,&b);
51         int ans=0;
52         for(int j=1;j<=m;j++)
53         {
54             if(find(a,j)==find(b,j))
55                 ans++;
56         }
57         printf("%d
",ans);
58     }
59     return 0 ;
60 }
原文地址:https://www.cnblogs.com/hsd-/p/7191712.html