BNUOJ-26480 Horror List 最短路

　　题目链接：http://www.bnuoj.com/bnuoj/problem_show.php?pid=26480

　　题意：简单来说，就是给一个图，然后从每个honor list中的点求最短路。。

　　边权值为1，Bfs就可以了，注意这里是无向图。。

  1 //STATUS:C++_AC_84MS_1788KB

  2 #include <functional>

  3 #include <algorithm>

  4 #include <iostream>

  5 //#include <ext/rope>

  6 #include <fstream>

  7 #include <sstream>

  8 #include <iomanip>

  9 #include <numeric>

 10 #include <cstring>

 11 #include <cassert>

 12 #include <cstdio>

 13 #include <string>

 14 #include <vector>

 15 #include <bitset>

 16 #include <queue>

 17 #include <stack>

 18 #include <cmath>

 19 #include <ctime>

 20 #include <list>

 21 #include <set>

 22 //#include <map>

 23 using namespace std;

 24 //#pragma comment(linker,"/STACK:102400000,102400000")

 25 //using namespace __gnu_cxx;

 26 //define

 27 #define pii pair<int,int>

 28 #define mem(a,b) memset(a,b,sizeof(a))

 29 #define lson l,mid,rt<<1

 30 #define rson mid+1,r,rt<<1|1

 31 #define PI acos(-1.0)

 32 //typedef

 33 typedef long long LL;

 34 typedef unsigned long long ULL;

 35 //const

 36 const int N=1010;

 37 const int INF=0x3f3f3f3f;

 38 const int MOD=1e9+7,STA=8000010;

 39 //const LL LNF=1LL<<60;

 40 const double EPS=1e-8;

 41 const double OO=1e15;

 42 const int dx[4]={-1,0,1,0};

 43 const int dy[4]={0,1,0,-1};

 44 const int day[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};

 45 //Daily Use ...

 46 inline int sign(double x){return (x>EPS)-(x<-EPS);}

 47 template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}

 48 template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}

 49 template<class T> inline T lcm(T a,T b,T d){return a/d*b;}

 50 template<class T> inline T Min(T a,T b){return a<b?a:b;}

 51 template<class T> inline T Max(T a,T b){return a>b?a:b;}

 52 template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);}

 53 template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);}

 54 template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));}

 55 template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));}

 56 //End

 57 

 58 struct Edge{

 59     int u,v;

 60 }e[N*10*2];

 61 int first[N],next[N*10*2],vis[N],hig[N];

 62 int n,m,L,mt;

 63 

 64 void adde(int a,int b)

 65 {

 66     e[mt].u=a,e[mt].v=b;

 67     next[mt]=first[a],first[a]=mt++;

 68     e[mt].u=b,e[mt].v=a;

 69     next[mt]=first[b],first[b]=mt++;

 70 }

 71 

 72 queue<int> q;

 73 void bfs()

 74 {

 75     int i,j,u,v;

 76     while(!q.empty())

 77     {

 78         u=q.front();q.pop();

 79         for(i=first[u];i!=-1;i=next[i]){

 80             v=e[i].v;

 81             if(vis[v])continue;

 82             vis[v]=1;

 83             hig[v]=hig[u]+1;

 84             q.push(v);

 85         }

 86     }

 87 }

 88 

 89 int main()

 90 {

 91  //   freopen("in.txt","r",stdin);

 92     int i,j,k,a,b,c;

 93     while(~scanf("%d%d%d",&n,&m,&L))

 94     {

 95         mem(first,-1);mt=0;

 96         mem(hig,INF);

 97         mem(vis,0);

 98         for(i=0;i<m;i++){

 99             scanf("%d",&a);

100             hig[a]=0;

101             q.push(a);

102             vis[a]=1;

103         }

104         for(i=0;i<L;i++){

105             scanf("%d%d",&a,&b);

106             adde(b,a);

107         }

108 

109         bfs();

110         int ans=0,answ=0;

111         for(i=0;i<n;i++){

112             if(hig[i]>ans){

113                 ans=hig[i];

114                 answ=i;

115             }

116         }

117 

118         printf("%d\n",answ);

119     }

120     return 0;

121 }