sap模板

int n, g[maxn][maxn], dis[maxn], vd[maxn];
int dfs(int u, int flow)
{
	int temp, v, delta;
	if(u==n)return flow;
	delta=0;
	for(v=1; v<=n; v++)
	{
		if(g[u][v]>0&&dis[u]==dis[v]+1)
		{
			temp=dfs(v, Min(flow-delta, g[u][v]));
			g[u][v]-=temp;
			g[v][u]+=temp;
			delta+=temp;
			if(delta==flow||dis[1]>=n)return delta;
		}
	}
	if(dis[1]>=n)return delta;
	vd[dis[u]]--;
	if(vd[dis[u]]==0)dis[1]=n;
	dis[u]++;
	vd[dis[u]]++;
	return delta;
}
int main()
{
	while(dis[1]<n)
	{
		ans+=dfs(1, inf);
	}
	printf("%d", ans);
	return 0;
}