UVA 753（最大流匹配）

来源：互联网发布：mac怎么彻底删除软件编辑：程序博客网时间：2024/05/22 01:37
s - ＞往M个设备流1，然后每个设备往对应插口号流1，然后插口号之间的K个转换边流无穷大（代表该装备能被利用无穷遍），然后插排号流1到对应的N个插排，然后每个插排流1到汇点。
//#pragma comment(linker, "/STACK:1024000000,1024000000")#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#include <vector>#include <set>#include <map>#include <string>#include <list>#include <cstdlib>#include <queue>#include <stack>#include <cmath>#define ALL(a) a.begin(), a.end()#define clr(a, x) memset(a, x, sizeof a)#define fst first#define snd second#define pb push_back#define lowbit(x) (x&(-x))#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1#define rep1(i,x,y) for(int i=x;i<=y;i++)#define rep(i,n) for(int i=0;i<(int)n;i++)using namespace std;const double eps = 1e-10;typedef long long LL;typedef long long ll;typedef pair<int, int> pii;const int oo =0x3f3f3f3f;const int maxn = 401;const int maxm = 500;map<string,int> M;int cnt_,rec[maxn] , plu[maxn];int ID(string s){   if(M.count(s)) return M[s];   return M[s] = cnt_++;}struct Edge{    int u, v, cap, flow;    Edge(int u, int v, int c, int f):u(u), v(v), cap(c), flow(f) {}};struct Dinic{    int n, m, s, t, d[maxn], cur[maxn];    bool vis[maxn];    vector<Edge> edge;    vector<int> G[maxn];    void init(int n)    {        this->n=n;        for(int i=0; i<=n; i++)            G[i].clear();        edge.clear();    }    int AddEdge(int u, int v, int c)    {        edge.push_back(Edge(u, v, c, 0));        edge.push_back(Edge(v, u, 0, 0));        m=edge.size();        G[u].push_back(m-2);        G[v].push_back(m-1);        return m-2;    }    bool bfs()    {        clr(vis, 0);        queue<int> q;        q.push(s);        d[s]=0, vis[s]=1;        while(!q.empty())        {            int x=q.front();            q.pop();            for(int i=0; i<G[x].size(); i++)            {                Edge& e=edge[G[x][i]];                if(!vis[e.v] && e.cap>e.flow)                {                    vis[e.v]=1;                    d[e.v]=d[x]+1;                    q.push(e.v);                }            }        }        return vis[t];    }    int dfs(int x, int a)    {        if(x==t || a==0)return a;        int flow=0, f;        for(int& i=cur[x]; i<G[x].size(); i++)        {            Edge& e=edge[G[x][i]];            if(d[x]+1==d[e.v] && (f=dfs(e.v, min(a, e.cap-e.flow)))>0)            {                e.flow+=f;                edge[G[x][i]^1].flow-=f;                flow+=f;                a-=f;                if(a==0)break;            }        }        return flow;    }    int MaxFlow(int s, int t)    {        this->s=s;        this->t=t;        int flow=0;        while(bfs())        {            clr(cur, 0);            flow+=dfs(s, oo);        }        return flow;    }} net;int S,T,n,m,k,f[maxn],t[maxn];int main(){   //ios::sync_with_stdio(false);   int Ta;   scanf("%d",&Ta);   while(Ta--){      scanf("%d",&n);      cnt_ = 1 , M.clear();      string str , src;      char s[50];      clr(rec,0) , clr(plu,0);      rep1(i,1,n){         scanf("%s",s); src = s;         rec[ID(src)]++;      }      scanf("%d",&m);      char s1[50],s2[50];      rep1(i,1,m){         scanf("%s %s",s1,s2);         src = s2;         plu[ID(src)]++;      }      scanf("%d",&k);      rep1(i,1,k){        scanf("%s %s",s1,s2);        str = s1 , src = s2;        f[i] = ID(str),t[i]=ID(src);      }      S = 0 , T = cnt_;      net.init(T);      rep1(i,1,cnt_-1) if(plu[i]){         net.AddEdge(S,i,plu[i]);      }      rep1(i,1,cnt_-1) if(rec[i]){         net.AddEdge(i,T,rec[i]);      }      rep1(i,1,k) {        if(f[i] != t[i])        net.AddEdge(f[i],t[i],oo);      }      printf("%d\n",m-net.MaxFlow(S,T));      if(Ta) printf("\n");   }   return 0;}
0 0