保证满流的情况,最小化源点到制定点集上每条边的流量最大值。最小最大化问题惯用二分,SPOJ似乎很喜欢点标号乱搞?
/* Author : Speedcell Update : 2013-10-16 Version : soppYcell 2.4 */ #include <algorithm> #include <iostream> #include <fstream> #include <sstream> #include <iomanip> #include <map> #include <set> #include <list> #include <stack> #include <queue> #include <deque> #include <vector> #include <string> #include <bitset> #include <memory> #include <complex> #include <numeric> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include <time.h> #include <ctype.h> #include <assert.h> #include <locale.h> using namespace std; #pragma pack(4) #ifndef __CONSTANT__ #define __CONSTANT__ typedef long long LONG; const double pi = acos(-1.0); const int inf = 0x7f7f7f7f; const LONG INF = 0x7f7f7f7f7f7f7f7fll; const int go[8][2] = {{0,1},{0,-1},{1,0},{-1,0},{1,1},{1,-1},{-1,1},{-1,-1}}; #endif // __CONSTANT__ #ifndef __IO__ #define __IO__ inline bool RD(int & a) {return scanf("%d",&a)!=EOF;} inline bool RD(char & a) {return scanf("%c",&a)!=EOF;} inline bool RD(char * a) {return scanf("%s", a)!=EOF;} inline bool RD(double & a) {return scanf("%lf",&a)!=EOF;} inline bool RD(LONG & a) {return scanf("%I64d",&a)!=EOF;} template<class T1> inline bool IN(T1 & a) {return RD(a);} template<class T1,class T2> inline bool IN(T1 & a,T2 & b) {return RD(a)&&RD(b);} template<class T1,class T2,class T3> inline bool IN(T1 & a,T2 & b,T3 & c) {return RD(a)&&RD(b)&&RD(c);} template<class T1,class T2,class T3,class T4> inline bool IN(T1 & a,T2 & b,T3 & c,T4 & d) {return RD(a)&&RD(b)&&RD(c)&&RD(d);} template<class T1,class T2,class T3,class T4,class T5> inline bool IN(T1 & a,T2 & b,T3 & c,T4 & d,T5 & e) {return RD(a)&&RD(b)&&RD(c)&&RD(d)&&RD(e);} template<class T1,class T2,class T3,class T4,class T5,class T6> inline bool IN(T1 & a,T2 & b,T3 & c,T4 & d,T5 & e,T6 & f) {return RD(a)&&RD(b)&&RD(c)&&RD(d)&&RD(e)&&RD(f);} template<class T1,class T2,class T3,class T4,class T5,class T6,class T7> inline bool IN(T1 & a,T2 & b,T3 & c,T4 & d,T5 & e,T6 & f,T7 & g) {return RD(a)&&RD(b)&&RD(c)&&RD(d)&&RD(e)&&RD(f)&&RD(g);} inline void PT(int a) {printf("%d",a);} inline void PT(char a) {printf("%c",a);} inline void PT(char * a) {printf("%s",a);} inline void PT(double a) {printf("%f",a);} inline void PT(unsigned a) {printf("%u",a);} inline void PT(LONG a) {printf("%I64d",a);} inline void PT(string a) {printf("%s",a.c_str());} inline void PT(const char a[]) {printf("%s",a);} template<class T1> inline void OT(T1 a) {PT(a);} template<class T1,class T2> inline void OT(T1 a,T2 b) {PT(a),PT(' '),PT(b);} template<class T1,class T2,class T3> inline void OT(T1 a,T2 b,T3 c) {PT(a),PT(' '),PT(b),PT(' '),PT(c);} template<class T1,class T2,class T3,class T4> inline void OT(T1 a,T2 b,T3 c,T4 d) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d);} template<class T1,class T2,class T3,class T4,class T5> inline void OT(T1 a,T2 b,T3 c,T4 d,T5 e) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e);} template<class T1,class T2,class T3,class T4,class T5,class T6> inline void OT(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e),PT(' '),PT(f);} template<class T1,class T2,class T3,class T4,class T5,class T6,class T7> inline void OT(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f,T7 g) {PT(a),PT(' '),PT(b),PT(' '),PT(c),PT(' '),PT(d),PT(' '),PT(e),PT(' '),PT(f),PT(' '),PT(g);} template<class T1> inline void OL(T1 a) {OT(a),PT('\n');} template<class T1,class T2> inline void OL(T1 a,T2 b) {OT(a,b),PT('\n');} template<class T1,class T2,class T3> inline void OL(T1 a,T2 b,T3 c) {OT(a,b,c),PT('\n');} template<class T1,class T2,class T3,class T4> inline void OL(T1 a,T2 b,T3 c,T4 d) {OT(a,b,c,d),PT('\n');} template<class T1,class T2,class T3,class T4,class T5> inline void OL(T1 a,T2 b,T3 c,T4 d,T5 e) {OT(a,b,c,d,e),PT('\n');} template<class T1,class T2,class T3,class T4,class T5,class T6> inline void OL(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f) {OT(a,b,c,d,e,f),PT('\n');} template<class T1,class T2,class T3,class T4,class T5,class T6,class T7> inline void OL(T1 a,T2 b,T3 c,T4 d,T5 e,T6 f,T7 g) {OT(a,b,c,d,e,f,g),PT('\n');} #endif // __IO__ #ifndef __MACRO__ #define __MACRO__ #define ML(times) int tcase; IN(tcase); FOR(times,1,tcase) #define FOR(i,a,b) for(int i=int(a),_##i=int(b);i<=_##i;i++) #define DWN(i,b,a) for(int i=int(b),_##i=int(a);_##i<=i;i--) #define ECH(i,u,pre,next) for(int i=int(pre[u]);i!=-1;i=int(next[i])) #define MEM(a,v) memset(a,v,sizeof(a)) #define CLR(a,v) FOR(_i##a,0,sizeof(a)/sizeof(a[0])-1) a[_i##a]=v #define LOOP(a,n) \ FOR(_i##a,0,(n)-1) \ OT(a[_i##a]),OT(_i##a!=__i##a?' ':'\n') #define LOOP2(a,n,m) \ FOR(_i##a,0,(n)-1) FOR(_j##a,0,(m)-1) \ OT(a[_i##a][_j##a]),OT(_j##a!=__j##a?' ':'\n') #define LOOPG(G,n,pre,next) \ FOR(_i##a,0,(n)-1) ECH(_j##a,_i##a,pre,next) \ OL(_i##a,G[_j##a].v,G[_j##a].w) #endif // __MACRO__ #ifndef __BIT__ #define __BIT__ template<class T> inline T lb(T i) {return i&-i;} template<class T> inline T lc(T i) {return i<<1;} template<class T> inline T rc(T i) {return i<<1|1;} template<class T> inline T at(T a,int i) {return a& (T(1)<<i);} template<class T> inline T nt(T a,int i) {return a^ (T(1)<<i);} template<class T> inline T s1(T a,int i) {return a| (T(1)<<i);} template<class T> inline T s0(T a,int i) {return a&~(T(1)<<i);} #endif // __BIT__ #ifndef __COMPARER__ #define __COMPARER__ const double eps = 1e-8; inline int cmp(double a,double b=0) {return fabs(b-a)<eps?0:((b-a)<eps?+1:-1);} template<typename type> inline int cmp(type a,type b=0) {return a==b?0:(b<a?+1:-1);} template<typename type> inline bool gt(type a,type b) {return cmp(a,b)> 0;} template<typename type> inline bool ge(type a,type b) {return cmp(a,b)>=0;} template<typename type> inline bool eq(type a,type b) {return cmp(a,b)==0;} template<typename type> inline bool ne(type a,type b) {return cmp(a,b)!=0;} template<typename type> inline bool le(type a,type b) {return cmp(a,b)<=0;} template<typename type> inline bool ls(type a,type b) {return cmp(a,b)< 0;} template<typename type> inline type smax(type a,type b) {return gt(a,b)?a:b;} template<typename type> inline type smin(type a,type b) {return ls(a,b)?a:b;} #endif // __COMPARER__ const int MAXV = 5000; const int MAXE = 5000000; struct node { int v,w; }G[MAXE]; int _index,pre[MAXV],next[MAXE]; inline void clear(void) { _index=0; MEM(pre,-1); } inline void add(int u,int v,int w) { G[_index].v=v; G[_index].w=w; next[_index]=pre[u]; pre[u]=_index++; } int dis[MAXV],gap[MAXV],curr[MAXV],prev[MAXV],head[MAXV]; inline int SAP(int src,int des,int n) { int u=src,sum=0,cnt; memcpy(head,pre,MAXV-1); MEM(dis,0); MEM(gap,0); gap[0]=n; while(dis[src]!=n) { bool flag=false; for(int &i=head[u];i!=-1;i=next[i]) { int v=G[i].v; int w=G[i].w; if(w&&dis[u]==dis[v]+1) { curr[v]=i; prev[v]=u; flag=true; u=v; break; } } if(flag) { if(u==des) { cnt=inf; for(int i=des;i!=src;i=prev[i]) { cnt=smin(cnt,G[curr[i]].w); } for(int i=des;i!=src;i=prev[i]) { G[curr[i]].w-=cnt; G[curr[i]^1].w+=cnt; } sum+=cnt; u=src; } } else { if(!--gap[dis[u]]) break; else { dis[u]=n; head[u]=pre[u]; ECH(i,u,pre,next) { int v=G[i].v; int w=G[i].w; if(w) dis[u]=smin(dis[u],dis[v]+1); } gap[dis[u]]++; if(u!=src) u=prev[u]; } } } return sum; } int n,m,k,h[MAXV],u[MAXV],v[MAXV]; inline bool bin(int cap) { clear(); FOR(i,0,m-1) { add(u[i],v[i],cap); add(v[i],u[i],cap); } FOR(i,0,k-1) { add(h[i],0,1); add(0,h[i],0); } return SAP(1,0,n+1)==k; } inline LONG solve(void) { int l=0,r=n,mid,ans; while(l<=r) { mid=(l+r)/2; if(bin(mid)) { ans=mid; r=mid-1; } else l=mid+1; } return ans; } int main() { #ifndef ONLINE_JUDGE freopen("Smart Network Administrator.txt","r",stdin); #else #endif ML(times) { IN(n,m,k); FOR(i,0,k-1) IN(h[i]); FOR(i,0,m-1) IN(u[i],v[i]); OL(solve()); } return 0; }