Graph theory algorithm-network maximum flow "Ek;dinic"

graph theory algorithm-Network maximum flow template "Ek;dinic" ek Templates

Increase traffic by finding the minimum residue in the augmented residual network every time

const int Inf=1e9;int n,m,s,t;struct node{int v,cap;}; vector<node> map[100010];int flow[10010][10010];int a[100010];int pre[100010];int EK () {int maxf;//record maximum flow Queu    E<int> Q;        while (1) {memset (a,0,sizeof (a));        A[s]=inf;                Q.push (s);            while (!q.empty ()) {int U=q.front ();            Q.pop ();                for (int j=0;j<map[u].size (); j + +) {int v=map[u][j].v;                int cap=map[u][j].cap;                    if (!a[v]&&cap>flow[u][v]) {pre[v]=u;                    Q.push (v);                A[v]=min (A[u],cap-flow[u][v]);                }}} if (a[t]==0) break;            for (int u=t;u!=s;u=pre[u]) {flow[pre[u]][u]+=a[t];        flow[u][Pre[u]]-=a[t];    } Maxf+=a[t]; } return MAXF;}    int main () {cin>>n>>m>>s>>t; for (int i=1;i<=m;i++) {int u,v,dis;        cin>>u>>v>>dis;        Map[u].push_back (node) {V,dis});        Map[v].push_back (node) {u,0}),//** highlight * * Reverse edge must remember to build} int Ans=ek ();    cout<<ans; return 0;}

Dinic templates

Construct hierarchy + Block flow augmentation

const int Inf=1e9;int n,m;int s,t;int tot=1;struct node{int v,f,nxt;}    E[1000010];int head[100010];int lev[100010];//Record level void Add (int u,int v,int cap) {e[++tot].v=v;    E[tot].nxt=head[u];    E[tot].f=cap; Head[u]=tot;}    BOOL BFs () {queue<int> q;    memset (Lev,-1,sizeof (Lev));    Q.push (s);        lev[s]=0;        while (!q.empty ()) {int U=q.front ();        Q.pop ();            for (int i=head[u];i;i=e[i].nxt) {int v=e[i].v;                if (LEV[V]==-1&AMP;&AMP;E[I].F) {lev[v]=lev[u]+1;                if (v==t) return true;            Q.push (v); }}} return false;}        int dfs (int u,int cap) {if (u==t) return cap;    int flow=cap;        for (int i=head[u];i;i=e[i].nxt) {int v=e[i].v;            if (lev[v]==lev[u]+1&&flow&&e[i].f>0) {int F=dfs (v,min (FLOW,E[I].F));            Flow-=f;            E[i].f-=f;        E[i^1].f+=f; }} RETurn Cap-flow;}       int dinic () {int maxf=0; while (BFS ())//If S-T can be reached on the continuous structure of the hierarchy Maxf+=dfs (s,inf);//s-t, augmented with a blocking stream return MAXF;}    int main () {cin>>n>>m>>s>>t;        for (int i=1;i<=m;i++) {int u,v,w;        cin>>u>>v>>w;        Add (U,V,W);    Add (v,u,0);//** Highlight * * Reverse side must remember to build} dinic ();    cout<<maxf; return 0;}

Graph theory algorithm-network maximum flow "Ek;dinic"