hdu 1829（带权并查集）

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int MAXN=2004;
int n,m;
int fa[MAXN];
bool val[MAXN];

inline int read() {
int x=0;char c=getchar();
while (c<'0'||c>'9') c=getchar();
while (c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
return x;
}
int find(int x) {
if (x==fa[x]) return x;
int t=fa[x];
fa[x]=find(fa[x]);
val[x]=(val[x]+val[t])&1;
return fa[x];
}
inline void merge(int x,int y,int fx,int fy) {
fa[fy]=fx;
val[fy]=(val[x]-val[y]+1)&1;
}
int main() {
//  freopen("hdu 1829.in","r",stdin);
int kase=read();
for (int kas=1;kas<=kase;++kas) {
bool sus=false;
printf("Scenario #%d:\n",kas);
n=read(),m=read();
for (int i=1;i<=n;++i) fa[i]=i,val[i]=0;
for (register int i=0;i<m;++i) {
int x=read(),y=read();
if (sus) continue;
int fx=find(x),fy=find(y);
if (fx==fy) {
if (val[x]==val[y]) {
sus=true;
}
} else merge(x,y,fx,fy);
}
puts(sus?"Suspicious bugs found!\n":"No suspicious bugs found!\n");
}
return 0;
}