网络流最大流之Dinic算法模板

bool bfs(int x){memset(mark,-1,sizeof(mark));mark[x]=1;int que[maxn];int front=0,rear=0;que[rear++]=x;while(front!=rear){int k=que[front++];front%=maxn;for(int i=head[k];i!=-1;i=edge[i].next){int v=edge[i].v;if(mark[v]==-1&&edge[i].flow>0){mark[v]=mark[k]+1;que[rear++]=v;rear%=maxn;if(v==des)return true;}}}return false;}int dfs(int u){int Stack[maxn],cur[maxn];        memcpy(cur,head,sizeof(head));        int top=0;int res=0;        while(1)        {                if(u==des)                {                    int min=INF,loc;                    for(int i=0;i<top;i++){if(min>edge[Stack[i]].flow){min=edge[Stack[i]].flow;loc=i;}}                    for(int i=0;i<top;i++)                    {                            edge[Stack[i]].flow-=min;                            edge[Stack[i]^1].flow+=min;                    }                    res+=min;                    top=loc;                    u=edge[Stack[top]].u;                }                for(int i=cur[u];i!=-1;cur[u]=i=edge[i].next){if(edge[i].flow&&mark[u]+1==mark[edge[i].v])break;}                if(cur[u]!=-1)                {                    Stack[top++]=cur[u];                    u=edge[cur[u]].v;                }                else                {                    if(top==0)break;                    mark[u]=-1;                    u=edge[Stack[--top]].u;                }        }return res;}int Dinic(int x){int res=0;while(bfs(src))res+=dfs(src);return res;}