hdu 4786 Fibonacci Tree (最小、最大生成树)

struct node{
    int u,v,c;
}edge[100005];

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

int fa[100005];
int T,n,m;

int findFa(int x){
    return fa[x]==x?x:fa[x]=findFa(fa[x]);
}

int kruskal1(){
    rep(i,1,n) fa[i]=i;
    int res=0;
    rep(i,1,m){
        int fx=findFa(edge[i].u);
        int fy=findFa(edge[i].v);
        if(fx!=fy){
            fa[fx]=fy;
            res+=edge[i].c;
        }
    }
    int tx=findFa(1);
    rep(i,2,n) if(findFa(i)!=tx) return -1;
    return res;
}
int kruskal2(){
    rep(i,1,n) fa[i]=i;
    int res=0;
    rep2(i,m,1){
        int fx=findFa(edge[i].u);
        int fy=findFa(edge[i].v);
        if(fx!=fy){
            fa[fx]=fy;
            res+=edge[i].c;
        }
    }
    int tx=findFa(1);
    rep(i,2,n) if(findFa(i)!=tx) return -1;
    return res;
}

bool isFibo[100005];

void FiboD(){
    mem(isFibo,false);
    int a=1,b=2; isFibo[1]=isFibo[2]=true;
    for(;;){
        int t=a+b;
        a=b, b=t;
        if(t>100000) break;
        isFibo[t]=true;
    }
}

int main(){
    //freopen("test.in","r",stdin);
    cin>>T;
    FiboD();
    rep(t,1,T){
        scanf("%d%d",&n,&m);
        rep(i,1,m)
            scanf("%d%d%d",&edge[i].u,&edge[i].v,&edge[i].c);
        sort(edge+1,edge+1+m,cmp);
        int mins=kruskal1();
        int maxs=kruskal2();

        printf("Case #%d: ",t);
        if(mins==-1 || maxs==-1) puts("No");
        else{
            bool flag=false;
            rep(i,mins,maxs) if(isFibo[i]){
                flag=true;
                break;
            }
            if(flag) puts("Yes"); else puts("No");
        }
    }
    //fclose(stdin);
}