hdu4263 Red/Blue Spanning Tree

思路：把红边设为1，蓝边设为2，求一次红色优先的最小生成树，得出最少的蓝边数，再蓝色优先求一次最小生成树，得出最多的蓝边数，最后只要K在这个范围内就可以

code：

/*    ID:yueqi    LANG:C++    TASK:humble*/#include <set>#include <map>#include <ctime>#include <queue>#include <cmath>#include <stack>#include <limits.h>#include <vector>#include <bitset>#include <string>#include <cstdio>#include <cstring>#include <fstream>#include <string.h>#include <iostream>#include <algorithm>#define Si set<int>#define LL long long#define pb push_back#define PS printf(" ")#define Vi vector<int>#define LN printf("\n")#define lson l,m,rt << 1#define rson m+1,r,rt<<1|1#define SD(a) scanf("%d",&a)#define PD(a) printf("%d",a)#define SET(a,b) memset(a,b,sizeof(a))#define FF(i,a) for(int i(0);i<(a);i++)#define FD(i,a) for(int i(a);i>=(1);i--)#define FOR(i,a,b) for(int i(a);i<=(b);i++)#define FOD(i,a,b) for(int i(a);i>=(b);i--)#define readf freopen("humble.in","r",stdin)#define writef freopen("humble.out","w",stdout)const int maxn = 1001;const long long BigP=999983;const long long  INF = 0x5fffffff;const int dx[]={-1,0,1,0};const int dy[]={0,1,0,-1};const double pi = acos(-1.0);const double eps= 1e-7;using namespace std;int N,M,K,father[maxn],rank[maxn];struct edge{    int u,v;    int col;//col==1 red,col==2 blue;}Edge[maxn*maxn];bool cmp1(const edge a,const edge b){    return a.col<b.col;}bool cmp2(const edge a,const edge b){    return a.col>b.col;}void initUnion(){    FOR(i,1,N){        father[i]=i;        rank[i]=0;    }}int find(int k){    return k==father[k] ? k:father[k]=find(father[k]);}void Union(int x,int y){    if(rank[x]<rank[y]){        father[x]=y;    }else{        father[y]=x;        if(rank[x]==rank[y]) rank[x]++;    }}int kruskal(){    int blue_cnt=0;    int cnt=0;    FOR(i,1,M){        int x=find(Edge[i].u);        int y=find(Edge[i].v);        if(x!=y){            Union(x,y);            cnt++;            if(Edge[i].col==2)                blue_cnt++;            if(cnt==N-1) break;        }    }    return blue_cnt;}int main(){    while(~scanf("%d%d%d",&N,&M,&K)&&(N+M+K)){        initUnion();        char buf[2];        int u,v;        FOR(i,1,M){            scanf("%s",buf);            scanf("%d%d",&u,&v);            Edge[i].u=u;            Edge[i].v=v;            if(buf[0]=='R') Edge[i].col=1;            else Edge[i].col=2;        }        //最小蓝色生成树        sort(Edge+1,Edge+M+1,cmp1);        int minn=kruskal();        initUnion();        //最小红色        sort(Edge+1,Edge+M+1,cmp2);        int maxx=kruskal();        if(K>=minn&&K<=maxx) puts("1");        else puts("0");    }    return 0;}