「CCO 2021」商旅

#include<cstdio>
#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<queue>
#include<cassert>
using namespace std;
#define ll long long 
#define ri int
#define pii pair<int,int>
const ll mod=998244353;
ll add(ll x,ll y){return (x+=y)<mod?x:x-mod;}
ll dec(ll x,ll y){return (x-=y)<0?x+mod:x;}
ll ksm(ll d,ll t,ll res=1){for(;t;t>>=1,d=d*d%mod) if(t&1) res=res*d%mod;return res;}
const int MAXN=2e5+7;
int n,m;
struct edge{
    int u,v,r,w;
    bool operator<(const edge p)const{
        return r<p.r;
    }
}e[MAXN];
const int inf=2e9;
int f[MAXN],cnt;
bool cmp(int x,int y){return e[x].w<e[y].w;}
vector<int> g[MAXN],rg[MAXN];
int ans[MAXN],mark[MAXN],deg[MAXN],del[MAXN];
int main(){
    // freopen("rand.in","r",stdin);
    // freopen("1.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(ri i=1;i<=n;++i) ans[i]=inf;
    for(ri i=1;i<=m;++i){
        int u,v,r,w;scanf("%d%d%d%d",&u,&v,&r,&w);
        e[i]=(edge){u,v,r,w};
    }
    sort(e+1,e+m+1);
    for(ri i=1;i<=m;++i) g[e[i].u].push_back(i),rg[e[i].v].push_back(i);
    for(ri i=1;i<=m;++i) deg[e[i].u]++;
    queue<int> q;
    for(ri i=1;i<=n;++i) if(!deg[i]) q.push(i);
    while(!q.empty()){
        int u=q.front();q.pop();
        mark[u]=1;
        for(auto x:rg[u]){
            del[x]=1;
            int v=e[x].u;
            if(!--deg[v]) q.push(v);
        }
    }
    for(ri i=m;i;--i){
        if(del[i]) continue;
        del[i]=1;
        ans[e[i].u]=min(ans[e[i].u],e[i].r);
        if(!--deg[e[i].u]) q.push(e[i].u);
        while(!q.empty()){
            int u=q.front();q.pop();
            assert(!mark[u]);
            mark[u]=1;
            for(auto x:rg[u]) {
                if(del[x]) continue;
                del[x]=1;
                ans[e[x].u]=min(ans[e[x].u],max(ans[u]-e[x].w,e[x].r));
                if(!--deg[e[x].u]) q.push(e[x].u);
            }
        }
    }
    for(ri i=1;i<=n;++i) printf("%d ",ans[i]==inf?-1:ans[i]);
}