ISAP

#include
    
     #include
     
      #include
      
       #include
       
        using namespace std;const int maxn = 1e5+11;const int oo = 0x7fffffff;int to[maxn<<1],nxt[maxn<<1],cap[maxn<<1],flow[maxn<<1];int head[maxn],tot;void init(){    memset(head,-1,sizeof head);    tot=0;}void add(int u,int v,int w){    to[tot]=v;    nxt[tot]=head[u];    cap[tot]=w;    flow[tot]=0;    head[u]=tot++;    swap(u,v);    to[tot]=v;    nxt[tot]=head[u];    cap[tot]=w;    flow[tot]=0;    head[u]=tot++;}int n,m,s,t;int gap[maxn],dep[maxn],que[maxn];int cur[maxn],stk[maxn];void bfs(){    memset(dep,-1,sizeof dep);    memset(gap,0,sizeof gap);    gap[0]=1;    int front=0,rear=0;    que[rear++]=t;dep[t]=0;    while(front^rear){        int u = que[front++];        for(int i = head[u]; ~i; i = nxt[i]){            int v=to[i];            if(~dep[v])continue;            que[rear++]=v;            dep[v]=dep[u]+1;            gap[dep[v]]++;        }    }   }int isap(){    bfs();    memcpy(cur,head,sizeof head);    int ans=0,top=0,u=s;    while(dep[s]
        
         cap[stk[i]]-flow[stk[i]]){                    mn=cap[stk[i]]-flow[stk[i]];                    inser=i;                }            }            for(int i = 0; i < top; i++){                flow[stk[i]]+=mn;                flow[stk[i]^1]-=mn;            }            ans+=mn;            top=inser;            u=to[stk[top]^1];            continue;        }        bool flag=0;        int v;        for(int i = cur[u]; ~i; i = nxt[i]){            v=to[i];            if(cap[i]-flow[i]&&dep[v]+1==dep[u]){                flag=1;                cur[u]=i;                break;            }        }        if(flag){            stk[top++]=cur[u];            u=v;            continue;        }        int mn=n;        for(int i = head[u]; ~i; i = nxt[i]){            if(cap[i]-flow[i]&&dep[to[i]]
        
       
      
     
    

MCMF

#include
    
     #include
     
      #include
      
       #include
       
        using namespace std;const int maxn = 1e5+11;const int oo = 0x3f3f3f3f;int to[maxn<<1],cost[maxn<<1],cap[maxn<<1],flow[maxn<<1],nxt[maxn<<1];int head[maxn],tot;void init(){    memset(head,-1,sizeof head);    tot=0;}void add(int u,int v,int c,int w){    to[tot]=v;    cap[tot]=c;    flow[tot]=0;    cost[tot]=w;    nxt[tot]=head[u];    head[u]=tot++;    swap(u,v);    to[tot]=v;    cap[tot]=0;    flow[tot]=0;    cost[tot]=-w;    nxt[tot]=head[u];    head[u]=tot++;}struct QUEUE{    int que[maxn];    int front,rear;    void init(){front=rear=0;}    void push(int x){que[rear++]=x;}    int pop(){return que[front++];}    bool empty(){return front==rear;}}que;int n,m,s,t;bool vis[maxn];int pre[maxn],dis[maxn];bool spfa(){    que.init();    memset(vis,0,sizeof vis);    memset(pre,-1,sizeof pre);    memset(dis,oo,sizeof dis);    que.push(s);vis[s]=1;dis[s]=0;    while(!que.empty()){        int u=que.pop(); vis[u]=0;        for(int i = head[u]; ~i; i = nxt[i]){            int v=to[i],c=cap[i],f=flow[i],w=cost[i];            if(c>f&&dis[v]>dis[u]+w){                dis[v]=dis[u]+w;                pre[v]=i;                if(!vis[v]){                    que.push(v);                    vis[v]=1;                }            }        }    }    if(dis[t]==oo) return 0;    else return 1;}int mcmf(){    int mc=0,mf=0;    while(spfa()){        int tf=oo+1;        for(int i = pre[t]; ~i; i = pre[to[i^1]]){            tf=min(tf,cap[i]-flow[i]);        }        mf+=tf;        for(int i = pre[t]; ~i; i = pre[to[i^1]]){            flow[i]+=tf;            flow[i^1]-=tf;        }        mc+=dis[t]*tf;    }    return mc;}
       
      
     
    

ISAP2.0

#include
    
     using namespace std;const int maxn = 1e5+11;const int oo = 0x7fffffff;int to[maxn<<1],nxt[maxn<<1],cap[maxn<<1],flow[maxn<<1];int head[maxn],tot;void init(){    memset(head,-1,sizeof head);    tot=0;}void add(int u,int v,int w){    to[tot]=v;    nxt[tot]=head[u];    cap[tot]=w;    flow[tot]=0;    head[u]=tot++;    swap(u,v);    to[tot]=v;    nxt[tot]=head[u];    cap[tot]=0;    flow[tot]=0;    head[u]=tot++;}int n,m,s,t;int dis[maxn],pre[maxn],cur[maxn],gap[maxn];bool vis[maxn];struct QUEUE{    int que[maxn];    int front,rear;    void init(){front=rear=0;}    void push(int u){que[rear++]=u;}    int pop(){return que[front++];}    bool empty(){return front==rear;}}que;void bfs(){    memset(vis,0,sizeof vis);    que.init();    que.push(t);    vis[t]=1;dis[t]=0;    while(que.empty()^1){        int u = que.pop();        for(int i = head[u]; ~i; i = nxt[i]){            register int v=to[i],c=cap[i^1],f=flow[i^1];            if(!vis[v]&&c>f){                vis[v]=1;                dis[v]=dis[u]+1;                que.push(v);            }        }    }}int aug(){    int u=t,ans=oo;    while(u!=s){        ans=min(ans,cap[pre[u]]-flow[pre[u]]);        u=to[pre[u]^1];    }    u=t;    while(u!=s){        flow[pre[u]]+=ans;        flow[pre[u]^1]-=ans;        u=to[pre[u]^1];    }    return ans;}int isap(){    int ans=0;    bfs();    memset(gap,0,sizeof gap);    memcpy(cur,head,sizeof head);    for(int i = 1; i <= n; i++) gap[dis[i]]++;    int u = s;    while(dis[s]
     
      f&&dis[u]==dis[v]+1){                ok=1;                pre[v]=i;                cur[u]=i;                u=v;                break;            }        }        if(!ok){            int mn=n-1;            for(int i = head[u]; ~i; i = nxt[i]){                int v=to[i],c=cap[i],f=flow[i];                if(c>f) mn=min(mn,dis[v]);            }            if(--gap[dis[u]]==0) break;            dis[u]=mn+1;gap[dis[u]]++;cur[u]=head[u];            if(u!=s) u=to[pre[u]^1];        }    }    return ans;}