POJ2492-A Bug's Life-并查集扩展应用

#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std;

const int maxn=2010;
int T,n,m;

int fa[maxn],rela[maxn];

int Find(int x)
{
int t;
if(fa[x] == x) return x;
t = fa[x];
fa[x] = Find(fa[x]);
rela[x] = (rela[x]+rela[t]+1)%2;
return fa[x];
}

void Union(int x,int y)
{
int fx=Find(x),fy=Find(y);
fa[fx] = fy;
rela[fx] = (rela[y]-rela[x])%2;
}

int main()
{
scanf("%d",&T);
for(int kase=1;kase<=T;kase++)
{
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)
{
fa[i] = i;
rela[i] = 1;
}

int x,y,sus=0;
for(int i=0;i<m;i++)
{
scanf("%d%d",&x,&y);
if(Find(x) == Find(y))
{
if(rela[x] == rela[y]) sus=1;
}
else Union(x,y);
}
printf("Scenario #%d:\n",kase);

if(sus)
printf("Suspicious bugs found!\n\n");
else
printf("No suspicious bugs found!\n\n");
}
}