Mr. Kitayuta's Colorful Graph
原题链接 http://acm.hdu.edu.cn/showproblem.php?pid=3999
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
Note
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.
- 有m个颜色,在有向图中构建对点进行找祖归宗,输出联通线路的个数;
- 开始想到的便是并查集,不过不是太熟练,样例卡了几次,做了出来,就是并查集模板,但是要变成二维数组,最后进行查询即可。
-
#include<stdio.h> #include<string.h> int mapp[200][200]; void init()//初始化数组,为构建地图做准备 { for(int i=1; i<=100; i++) { for(int j=1; j<=100; j++) { mapp[i][j]=i; } } } int getf(int u,int v)//路径压缩 { if(mapp[u][v]==u) { return u; } else { return mapp[u][v]=getf(mapp[u][v],v); } } void merge(int u,int v,int w)//合并两子集合,找祖归宗 { int t1=getf(u,w); int t2=getf(v,w); if(t1!=t2) { mapp[t1][w]=t2; } } int main() { int n,m; while(~scanf("%d %d",&n,&m)) { init(); int a,b,c; for(int i=1; i<=m; i++) { scanf("%d%d%d",&a,&b,&c); merge(a,b,c); } int q,u,v; scanf("%d",&q);//q行开始输入ui与vi for(int i=0; i<q; i++) { scanf("%d %d",&u,&v); int ans=0; for(int i=1; i<=m; i++) { if(getf(u,i)==getf(v,i))//如果有祖宗相同的,便是一条联通路线 { ans++; } } printf("%d\n",ans); } } return 0; }