80分求助

#include <cstdio>
#include <algorithm>
#include <cstring>
#define MAXN 200010
#define MAXM 500010

using namespace std;

struct Edge{
    int to,nxt;
}edge[MAXM];

int ans,ans2;
int dfn[MAXN],low[MAXN];
int n,m,w[MAXN],u[MAXM],v[MAXM],head[MAXN],tot,idx,cnt;
int s[MAXN],top,vis[MAXN],f[MAXN],mf[MAXN],color[MAXN],sum[MAXN],maxsum[MAXN];

void add_edge(int fr,int to){
    edge[++tot].to=to;
    edge[tot].nxt=head[fr];
    head[fr]=tot;
}

void tarjan(int x){
    dfn[x]=low[x]=++idx;
    s[++top]=x;
    vis[x]=true;
    for(int e=head[x];e;e=edge[e].nxt){
        int v=edge[e].to;
        if(!dfn[v]){
            tarjan(v);
            low[x]=min(low[x],low[v]);
        }else if(vis[v]){
            low[x]=min(low[x],dfn[v]);
        }
    }
    if(dfn[x]==low[x]){
        ++cnt;
        while(s[top+1]!=x){
            color[s[top]]=cnt;
            sum[cnt]+=w[s[top]];
            maxsum[cnt]=max(maxsum[cnt],w[s[top]]);
            vis[s[top--]]=false;
        }
    }
}

void dfs(int x){
    if(f[x]) return;
    int res=0;
    f[x]=sum[x];
    mf[x]=maxsum[x];
    for(int e=head[x];e;e=edge[e].nxt){
        int v=edge[e].to;
        if(!f[v]) dfs(v);
        if(res<=f[v]){
            res=f[v];
            mf[x]=max(mf[x],mf[v]);
        }
    }
    f[x]+=res;
}

int main(){
    // freopen("in","r",stdin);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i){
        scanf("%d",&w[i]);
    }
    for(int i=0;i<m;++i){
        scanf("%d%d",&u[i],&v[i]);
        add_edge(u[i],v[i]);
    }
    for(int i=1;i<=n;++i){
        if(!dfn[i]){
            tarjan(i);
        }
    }
    memset(head,0,sizeof(head));
    tot=0;
    for(int i=0;i<m;++i){
        if(color[u[i]]!=color[v[i]]){
            add_edge(color[u[i]],color[v[i]]);
        }
    }
    for(int i=1;i<=cnt;++i){
        if(!f[i]){
            dfs(i);
            if(ans<=f[i]){
                ans=f[i];
                ans2=max(ans2,mf[i]);
            }
        }
    }
    printf("%d %d",ans,ans2);
    return 0;
}