ACM: Mr. Kitayuta's Colorful Graph-并查集-解题报

Mr. Kitayuta's Colorful Graph
Time Limit:1000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u

Description
Mr. Kitayuta has just bought an undirected graph consisting of n vertices and m edges. The vertices of the graph are numbered from  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 ( ≤ n ≤ ,  ≤ m ≤ ), denoting the number of the vertices and the number of the edges, respectively.

The next m lines contain space-separated three integers — ai, bi ( ≤ ai < bi ≤ n) and ci ( ≤ 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 ( ≤ q ≤ ), denoting the number of the queries.

Then follows q lines, containing space-separated two integers — ui and vi ( ≤ ui, vi ≤ n). It is guaranteed that ui ≠ vi.

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

Sample Input
Input

Output

Input

Output

Hint
Let's consider the first sample.

 The figure above shows the first sample.
Vertex  and vertex  are connected by color  and .
Vertex  and vertex  are connected by color .
Vertex  and vertex  are not connected by any single color.

题目还是比较水，很简单的并查集，思路清晰就够了；
AC代码：

#include"iostream"
#include"cstdio"
#include"cstring"
#include"cmath"
#include"algorithm"
using namespace std;
const int MX=110;
int CL[101];
struct nde {
	int	p[MX];	//记录每个颜色下的根
} cmap[MX];

struct node {
	int a,b,c; //连接的点 a b 和颜色c
} side[MX];

bool cmps(node a,node b) {
	return a.c<b.c;
}

struct nod {
	int u,v;	//查询组
} Que[MX];

int find(int x,int c) {
	return cmap[c].p[x]==x?x:(cmap[c].p[x]=find(cmap[c].p[x],c)); //找到在颜色C下的根。
}

void init() {				//清空并初始化整个颜色图。
	for(int i=1; i<=100; i++)
		for(int j=1; j<=100; j++) {
			cmap[i].p[j]=j;
		}
}

int main() {
	int n,m,q;
	while(~scanf("%d%d",&n,&m)) {
		init();
		for(int i=1; i<=m; i++) {		//把整个输入先全部记录下
			scanf("%d%d%d",&side[i].a,&side[i].b,&side[i].c);
		}
		sort(side+1,side+1+m,cmps);//按照颜色排序；
		int tot=1;		//tot 记录颜色的种类
		CL[tot]=side[1].c;//记录下出现过的颜色
		for(int i=1; i<=m; i++) {
			if(side[i].c!=CL[tot]) {	//如果下一个颜色与上一个颜色不同记录进数组  CL
				CL[++tot]=side[i].c;
			}
			int rt1=find(side[i].a,side[i].c);  	//找到在颜色 C 下的根
			int rt2=find(side[i].b,side[i].c);
			if(rt1!=rt2) {
				cmap[side[i].c].p[rt2]=rt1;	//在颜色 C下将两点连接，更新根
			}
		}
		scanf("%d",&q);
		for(int i=1; i<=q; i++) {
			scanf("%d%d",&Que[i].u,&Que[i].v);	//单组输入查询
			int ans=0;
			for(int j=1; j<=tot; j++) {			//每个出现过的颜色下都查询一次
				int rt1=find(Que[i].u,CL[j]);
				int rt2=find(Que[i].v,CL[j]);
				if(rt1==rt2)ans++;				//如果是一个联通块答案加一
			}
			printf("%d\n",ans);					//输出该组的答案
		}
	}
	return 0;
}