bzoj 4519: [Cqoi2016]不同的最小割

#include<cstdio>

#include<cstdlib>

#include<cstring>

#include<algorithm>

#include<set>

#define ll long long

#define inf 1e9

#define eps 1e-8

#define md

#define N 900

using namespace std;

set<int> st;

struct yts { int x,t,f,ne;} e[20010],p[20010];

int v[N],q[N],dep[N],g[N];

bool vis[N];

int S,T,num,m,tot=0;

void put(int x,int y,int f)

{

num++; e[num].x=x; e[num].t=y; e[num].f=f;

e[num].ne=v[x]; v[x]=num;

}

void add(int x,int y,int f)

{

put(x,y,f); put(y,x,f);

}

bool bfs()

{

memset(dep,0,sizeof(dep));

int h=0,w=1; q[1]=S; dep[S]=1;

while (h!=w)

{

int x=q[++h];

for (int i=v[x];i;i=e[i].ne)

{

int y=e[i].t;

if (e[i].f&&!dep[y])

{

dep[y]=dep[x]+1;

q[++w]=y;

}

}

}

return dep[T]>0;

}

int dfs(int x,int flow)

{

if (x==T) return flow;

int used=0,now=0;

for (int i=v[x];i;i=e[i].ne)

{

int y=e[i].t;

if (e[i].f&&dep[y]==dep[x]+1)

{

now=dfs(y,min(flow-used,e[i].f));

e[i].f-=now; e[i^1].f+=now;

used+=now; if (flow==used) break;

}

}

if (!used) dep[x]=-1;

return used;

}

int dinic(int s,int t)

{

S=s; T=t;

int ans=0;

while (bfs()) ans+=dfs(S,inf);

return ans;

}

void get(int x)

{

vis[x]=1;

for (int i=v[x];i;i=e[i].ne)

{

int y=e[i].t;

if (e[i].f&&!vis[y]) get(y);

}

}

void solve(int l,int r)

{

if (l>=r) return;

memset(v,0,sizeof(v)); num=1;

for (int i=1;i<=m;i++) add(p[i].x,p[i].t,p[i].f);

int ans=dinic(g[l],g[r]);

if (st.find(ans)==st.end()) { tot++; st.insert(ans); }

memset(vis,0,sizeof(vis));

get(g[l]);

int w=l-1;

for (int i=l;i<=r;i++)

if (vis[g[i]]) swap(g[++w],g[i]);

solve(l,w); solve(w+1,r);

}

int main()

{

int n;

scanf("%d%d",&n,&m);

for (int i=1;i<=m;i++) scanf("%d%d%d",&p[i].x,&p[i].t,&p[i].f);

for (int i=1;i<=n;i++) g[i]=i;

tot=0;

solve(1,n);

printf("%d\n",tot);

return 0;

}