题目链接

这个题,一眼看上去就是最短路的题,边权有负环显然不能用dij,然后出题人又卡了spfa,,那怎么办的想点办法啊,好像还有一个拓扑排序可以求最短路吧,这时候正解就已经得到了,就是拓扑排序求最短路。
在求拓扑序的时候,每次入队时,将这个入队的点所拓展出来的点都进行松弛操作,就可以啦,复杂度O(E+V),后面的判断还要注意一下。就做完啦。

#include <set>
#include <map>
#include <queue>
#include <stack>
#include <math.h>
#include <bitset>
#include <vector>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#define MAXN 1010100
#define LL long long
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ll __int64
#define INF 0x7fffffff
#define cs(s) freopen(s,"r",stdin)
#define mem(x) memset(x,0,sizeof(x))
#define PI acos(-1)
#define eps 1e-10
using namespace std;
int gcd(int a,int b){return b?gcd(b,a%b):a;}
int lcm(int a,int b){return a/gcd(a,b)*b;}
LL powmod(LL a,LL b,LL MOD){LL ans=1;while(b){if(b%2)ans=ans*a%MOD;a=a*a%MOD;b/=2;}return ans;}
//head
vector<pair<int,pair<LL,pair<LL,LL> > > >v[100001];
LL disa[100001],disb[100001];
int inq[100001];
int du[100001],dd[100001];
int main(){
    ios::sync_with_stdio(false);
    int tt;
    for(cin>>tt;tt;tt--){
        int n,m;
        cin>>n>>m;
        for(int i=1;i<=n;i++)v[i].clear(),disa[i]=1e18,disb[i]=1e18,inq[i]=du[i]=dd[i]=0;
        disa[1]=disb[1]=0;
        for(int i=1;i<=m;i++){
            int s,t;
            LL c,cb,jff;
            cin>>s>>t>>c>>cb>>jff;
            v[s].pb({t,{c,{-cb,-jff}}});
            du[t]++;
            dd[t]++;
        }
        queue<int>p,q;
        while(!p.empty())p.pop();
        while(!q.empty())q.pop();
        for(int i=1;i<=n;i++){
            if(!du[i]){
                p.push(i);
                for(auto k:v[i]){
                    if(disa[k.fi]>disa[i]+k.se.fi+k.se.se.fi){
                        disa[k.fi]=disa[i]+k.se.fi+k.se.se.fi;
                    }
                }
            }
            if(!dd[i]){
                q.push(i);
                for(auto k:v[i]){
                    if(disb[k.fi]>disb[i]+k.se.fi+k.se.se.se){
                        disb[k.fi]=disb[i]+k.se.fi+k.se.se.se;
                        //cout<<k.fi<<' '<<disb[k.fi]<<endl;
                    }
                }
            }
        }
        while(!p.empty()){
            int now=p.front();
            p.pop();
            for(auto k:v[now]){
                --du[k.fi];
                if(!du[k.fi]){
                    p.push(k.fi);
                    for(auto kk:v[k.fi]){
                        if(disa[kk.fi]>disa[k.fi]+kk.se.fi+kk.se.se.fi){
                            disa[kk.fi]=disa[k.fi]+kk.se.fi+kk.se.se.fi;
                        }
                    }
                }
            }
        }
        while(!q.empty()){
            int now=q.front();
            q.pop();
            for(auto k:v[now]){
                --dd[k.fi];
                if(!dd[k.fi]){
                    q.push(k.fi);
                    for(auto kk:v[k.fi]){
                        if(disb[kk.fi]>disb[k.fi]+kk.se.fi+kk.se.se.se){
                            disb[kk.fi]=disb[k.fi]+kk.se.fi+kk.se.se.se;
                        }
                    }
                }
            }
        }      
        swap(disa[n],disb[n]);
        disa[n]=max(disa[n],0ll);
        if(disa[n]==0&&disb[n]<=0){
            cout<<"oof!!!\n";
        }else {
            if(disb[n]<=0){
                cout<<"cnznb!!!\n";
                cout<<disa[n]<<endl;
            }else{
                if(disb[n]>disa[n]){
                    cout<<"rip!!!\n";
                    cout<<disb[n]-disa[n]<<endl;
                }else{
                    cout<<"cnznb!!!\n";
                    cout<<disa[n]-disb[n]<<endl;
                }
            }
        }
    }
    return 0;
}