Hdu-6200 mustedge mustedge mustedge(动态树+并查集)

Give an connected undirected graph with n nodes and m edges, (n,m≤105) which has no selfloops or multiple edges initially.
Now we have q operations (q≤105):
  
⋅1 u v: add an undirected edge from u to v; (u≠v&&1≤u,v≤n)
⋅2 u v: count the number of mustedges from u to v; (1≤u,v≤n).

mustedge: we define set Ei as a path from u to v which contain edges in this path, and |∩k1Ei| is the number of mustedges. |x| means size of set x, and E1,E2…Ek means all the paths.
It's guaranteed that ∑n,∑m,∑q≤106

Please note that maybe there are more than one edges between two nodes after we add edges. They are not the same, which means they can be in a set at the same time. Read the sample data for more information.

Input

Input starts with an integer T, denoting the number of test cases.
For each case:
First line are two number n and m;
Then next m lines, each contains two integers u and v, which indicates an undirected edge from u to v;
Next line contains a number q, the number of operations;
Then next q lines, contains three integers x, u and v where x

is the operation type, which describes an operation.

Output

For each test case, output "Case #x:" where x is the test case number starting from 1.
In each test case, print a single number one line when query the number of mustedges

.

Sample Input

2
4 3
1 2
2 3
3 4
5
2 1 4
1 2 3
2 1 4
2 2 3
2 2 4
8 9
1 2
2 3
1 3
3 4
4 5
4 6
5 7
5 8
7 8
5
2 7 8
2 1 6
2 4 7
1 6 8
2 5 6

Sample Output

Case #1:
3
2
0
1
Case #2:
0
2
1
0

题意：大概就是给你一个图,可以动态加边,每次询问从u到v要经过几个桥边,还是一样的套路,用并查集+LCT动态维护缩点后的树,有点卡常,加了fread才过了。

#include <queue>
#include <cstdio>
#include <cstring> 
#include <iostream>
#define INF 2147483640
#define eps 1e-9
using namespace std;
const int MAXN = 2e5 + 10;
int n,m,q,f[MAXN],f2[MAXN],s[MAXN],ch[MAXN][2],val[MAXN],sum[MAXN],fa[MAXN];
bool lazy[MAXN];
inline int nextChr()
{
    static const int siz=1<<22;
    static char buf[siz],*chr=buf+siz;
    if(chr==buf+siz)fread(chr=buf,1,siz,stdin);
    return int(*chr++);
}
inline int read()
{
    register int r=0,c=nextChr();
    for(;c<48;c=nextChr());
    for(;c>47;c=nextChr())r=(r<<3)+(r<<1)+c-48;
    return r;
}    
inline int Find(int x)
{
	if(f[x] == x) return x;
	f[x] = Find(f[x]);
	return f[x];
}
inline int Find2(int x)
{
	if(f2[x] == x) return x;
	f2[x] = Find2(f2[x]);
	return f2[x];
}
inline bool isroot(int x)
{
	return ch[Find(fa[x])][0] != x && ch[f[fa[x]]][1] != x;
}
void push_up(int x)
{
	int ls = ch[x][0],rs = ch[x][1];
	sum[x] = sum[ls] + sum[rs] + val[x]; 
}
void rotate(int x)
{
	int y = Find(fa[x]),z = Find(fa[y]);
	int d = ch[y][0] == x ? 0 : 1;
	if(!isroot(y))
	{
		if(ch[z][0] == y) ch[z][0] = x;
		else ch[z][1] = x;
	}
	fa[y] = x,fa[x] = z;fa[ch[x][d^1]] = y;
	ch[y][d] = ch[x][d^1],ch[x][d^1] = y;
	push_up(y),push_up(x);
}
inline void push_down(int x)
{
	if(!lazy[x]) return;
	int ls = ch[x][0],rs = ch[x][1];
	lazy[x] ^= 1;lazy[ls] ^= 1;lazy[rs] ^= 1;
	swap(ch[ls][0],ch[ls][1]);
	swap(ch[rs][0],ch[rs][1]);
}
void splay(int x)
{
	int tot = 0;s[++tot] = x;
	for(int i = x;!isroot(i);i = Find(fa[i])) s[++tot] = Find(fa[i]);
	for(;tot;tot--) push_down(s[tot]);
	while(!isroot(x))
	{
		int y = Find(fa[x]),z = Find(fa[y]);
		if(!isroot(y))
		{
			if((ch[z][0] == y) ^ (ch[y][0] == x)) rotate(x);
			else rotate(y);
		}
		rotate(x);
	}
}
void access(int x)
{
	int t = 0;
	while(x)
	{
		splay(x);
		ch[x][1] = t;
		push_up(x);
		t = x,x = Find(fa[x]);
	}
}
void makeroot(int x)
{
	access(x),splay(x);
	swap(ch[x][0],ch[x][1]);
	lazy[x] ^= 1;
}
void link(int x,int y)
{
	makeroot(x);fa[x] = y;
	f2[f2[x]] = y;
}
bool linked(int x,int y)
{
	return Find2(x) == Find2(y);
}
void rebuild(int x,int y)
{
	if(!x) return;
	f[f[x]] = y;
	rebuild(ch[x][0],y);
	rebuild(ch[x][1],y);
}
int main()
{
	int T = read();
	for(int Time = 1;Time <= T;Time++)
	{
		printf("Case #%d:\n",Time);
		n = read(),m = read();
		for(int i = 1;i <= 2*n;i++) f[i] = f2[i] = i,fa[i] = ch[i][0] = ch[i][1] = lazy[i] = 0;
		for(int i = 1;i <= n;i++) val[i] = sum[i] = 1;
		for(int i = 1;i <= m;i++)
		{
			int x = read(),y = read();
			if(!linked(Find(x),Find(y))) link(f[x],f[y]);
			else 
			{
				if(f[x] == f[y]) continue;
				makeroot(f[x]);
				access(f[y]);
				splay(f[y]);
				++n;
				val[n] = sum[n] = 1;
				f2[n] = f2[f[y]];
				rebuild(f[y],n);
			}
		}
		q = read();
		while(q--)
		{
			int p,x,y;
			p = read(),x = read(),y = read();
			if(p == 1)
			{
				if(!linked(Find(x),Find(y))) link(f[x],f[y]);
				else 
				{
					if(f[x] == f[y]) continue;
					makeroot(f[x]);
					access(f[y]);
					splay(f[y]);
					++n;
					val[n] = sum[n] = 1;
					f2[n] = f2[f[y]];
					rebuild(f[y],n);
				}
			}
			if(p == 2)
			{
				if(!linked(Find(x),Find(y))) printf("0\n");
				else 
				{
					makeroot(f[x]);
					access(f[y]);
					splay(f[y]);
					printf("%d\n",sum[f[y]]-1);
				}
			}
		}
	}
}