傳送門

預處理出所有人在第i天之前到達0所需要的最小花費sumT0[]
以及 所有人在第j天后回去所需要的最小花費sumF0[]

列舉開會時間i
則ans=min(sumT0[i−1]+sumF0[i+k]

#include<stdio.h>
#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define MEM(a,x) memset(a,x,sizeof(a))
#define lowbit(x) ((x)&-(x))
 


using namespace std;

const ll inf=1e18;
//const int INF = inf;

const int N = 1e5 + 5;
const int C = 1e6+5;

struct P{
    int d,t,c;
};
vector<P>to0,fr0;

bool cmp1(const P&a,const P&b){
    return a.d<b.d;
}

bool cmp2(const P&a,const P&b){
    return a.d>b.d;
}

ll sumF0[C],sumT0[C];
bool
 
 vis[N];
ll cost[N];
void updateSum(ll*sum,vector<P>&vec,int n){
    fill(vis,vis+n+1,0);
    fill(cost,cost+n+1,inf);
    fill(sum,sum+C,inf);
    int num=0;
    ll tmp=0;
    for(int i=0;i<vec.size();++i){
        P&p=vec[i];
        if(!vis[p.t]){
            ++num;
            vis[p.t]=1
 
;
            tmp+=p.c;
        }
        else{
            tmp=min(tmp,tmp-cost[p.t]+p.c);
        }
        if(num==n){
            sum[p.d]=min(sum[p.d],tmp);
        }
        cost[p.t]=min(cost[p.t],(ll)p.c);
    }
}

ll slove(int n,int k){
    sort(to0.begin(),to0.end(),cmp1);
    sort(fr0.begin(),fr0.end(),cmp2);
    updateSum(sumF0,fr0,n);
    updateSum(sumT0,to0,n);
    for(int i=2;i<C;++i){
        sumT0[i]=min(sumT0[i-1],sumT0[i]);
    }
    for(int i=C-2;i>=1;--i){
        sumF0[i]=min(sumF0[i+1],sumF0[i]);
    }
    ll ans=inf;
    for(int i=2;i+k<C;++i){
        ans=min(sumT0[i-1]+sumF0[i+k],ans);
    }
    return ans>=inf?-1:ans;
}

int main(){
    //freopen("/home/lu/code/r.txt","r",stdin);
    //freopen("/home/lu/code/w.txt","w",stdout);
    int n,m,k;
    while(~scanf("%d%d%d",&n,&m,&k)){
        int d,f,t,c;
        to0.clear();
        fr0.clear();
        while(m--){
            scanf("%d%d%d%d",&d,&f,&t,&c);
            if(f==0){
                fr0.push_back({d,t,c});
            }
            else{
                to0.push_back({d,f,c});
            }
        }
        printf("%lld\n",slove(n,k));
    }
    return 0;
}