无输出求调

#include<bits/stdc++.h>//洛谷P3387,[模板]缩点 
using namespace std;
const int N=1e5+5;
int n,m,cnt=0,num=0,top=0,cut=0;
int d[N],head[N],headd[N],w[N],dfn[N],low[N],stackk[N],dist[N],rd[N];//w是权值 
bool vis[N];
struct edge
{
	int to,nextt,from;
}e[N],ee[N];

void chushihua()
{
	memset(head,-1,sizeof(head));
	memset(headd,0,sizeof(headd));
	memset(dfn,0,sizeof(dfn));
	memset(low,0,sizeof(low));
	memset(w,0,sizeof(w));
}

void add(int u,int v)
{
	e[++cnt].to=v;
	e[cnt].nextt=head[u];
	e[cnt].from=u;
	head[u]=cnt;
}

void tarjan(int u)
{
	dfn[u]=low[u]=++num;
	stackk[++top]=u;vis[u]=1;
	for(int i=head[u];i!=-1;i=e[i].nextt)
	{
		int v=e[i].to;
		if(!dfn[v]==0)//父子边 
		{
			tarjan(v);
			low[u]=min(low[u],low[v]);
		}
		else if(vis[u]!=0)
		{
			low[u]=min(low[u],dfn[v]);
		}
	}
	if(dfn[u]==low[u])
	{
		int v;
		while(1)
		{
			v=stackk[--top];
			d[v]=u;
			vis[v]=0;
			if(v==u) break;
			w[u]+=w[v];
			
		}
	}
}

int topp()
{
	queue<int> q;
	for(int i=1;i<=n;i++)
	{
		if(!rd[i]&&d[i])
		{
			q.push(i);
			dist[i]=w[i];
		}
	}
	int ans;
	while(!q.empty())
	{
		int k=q.front();
		q.pop();
		for(int i=headd[k];i!=-1;i=ee[i].nextt)
		{
			int v=ee[i].to;
			dist[v]=max(dist[v],dist[k]+w[v]);
			rd[v]--;
			if(rd[v]==0) q.push(v);
		}
		
		for(int i=1;i<=n;i++)
		{
			ans=max(ans,dist[i]);
		}
	}
	return ans;
}

int main()
{
	cin>>n>>m;
	chushihua();
	for(int i=1;i<=n;i++)
	{
		cin>>w[i];
	}
	int u,v;
	for(int i=1;i<=m;i++)
	{
		cin>>u>>v;
		add(u,v);
	}
	for(int i=1;i<=n;i++)
	{
		if(!dfn[i]) tarjan(i);
	}
	for(int i=1;i<=m;i++)
	{
		int x=e[i].from,y=e[i].to;
		if(d[x]!=d[y])
		{
			ee[++cut].to=y;
			ee[cut].from=x;
			ee[cut].nextt=headd[x];
			headd[x]=cut;
			rd[y]++;
		}
	}
	cout<<topp();
	return 0;
}