最大流模版

来源：互联网发布：网络用语xjbs什么意思编辑：程序博客网时间：2024/05/21 06:12
poj1459
#include<iostream>#include<cstdio>#include<cstring>#include<cmath>#include<algorithm>#include<map>#include<set>#include<queue>#include<stack>#include<vector>using namespace std;typedef long long ll;#define mem(name,value) memset(name,value,sizeof(name))#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1const int maxn=210,maxm=110*110,inf=0x3f3f3f3f;struct Side{    int to,next,w;};struct Max_flow{    int node[maxn],dis[maxn],gap[maxn],top,cnt;    Side side[maxm*2];    void add_side(int u,int v,int w,int rw){        //cout<<u<<" "<<v<<" "<<w<<endl;        side[top]=(Side){v,node[u],w}; node[u]=top++;        side[top]=(Side){u,node[v],rw}; node[v]=top++;    }    void init(){        mem(node,-1); top=0;        mem(dis,0); mem(gap,0);    }    int get_flow(int u,int flow,int s,int t){        if(u==t)return flow;        int ans=0;        for(int i=node[u];i!=-1;i=side[i].next){            int v=side[i].to,w=side[i].w;            if(dis[u]>dis[v]&&w){                int f=get_flow(v,min(flow-ans,w),s,t);                ans+=f;                side[i].w-=f;                side[i^1].w+=f;                if(ans==flow) return ans;            }        }        if(!(--gap[dis[u]])) dis[s]=cnt+2;        gap[++dis[u]]++;        return ans;    }    int get_maxflow(int s,int t,int nn){        cnt=gap[s]=nn; int ans=0;        while(dis[s]<cnt) ans+=get_flow(s,inf,s,t);        return ans;    }}mf;int n,m,np,nc;int main(){    while(cin>>n>>np>>nc>>m){        mf.init();        int u,v,z;        while(m--){            scanf("%*[^(](%d,%d)%d",&u,&v,&z);            mf.add_side(u,v,z,0);        }        for(int i=1;i<=np;i++){            scanf("%*[^(](%d)%d",&u,&z);            mf.add_side(n,u,z,0);        }        for(int i=1;i<=nc;i++){            scanf("%*[^(](%d)%d",&u,&z);            mf.add_side(u,n+1,z,0);        }        int ans=mf.get_maxflow(n,n+1,n+2);        printf("%d\n",ans);    }}
0 0