Submission #862649

#	Time	Username	Problem	Language	Result	Execution time	Memory
862649		Ahmed57	Toll (BOI17_toll)	C++17	100 / 100	342 ms	51732 KiB

toll

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
long long k;vector<pair<int,int>> adj[100001],rev[1000001];
long long an[100001];
map<pair<int,int>,long long> mp;
void dc(int l,int r,vector<pair<pair<int,int>,int>> qu){
    if(l>=r)return;
    int md = (l+r)/2;
    long long ll[k][(int)k*(md-l+1)],rr[k][(k*(r-md))];
    for(int j = md;j>=l;j--){
        for(int z = 0;z<k;z++){
            for(int a = 0;a<k;a++){
                if(j==md){
                    if(z==a){
                        ll[a][((md+1)*k-1)-(j*k+z)] = 0;
                    }
                    else ll[a][((md+1)*k-1)-(j*k+z)] = 1e9;
                    continue;
                }
                ll[a][((md+1)*k-1)-(j*k+z)] = 1e9;
                for(auto e:adj[j*k+z]){
                    ll[a][((md+1)*k-1)-(j*k+z)] = min(ll[a][((md+1)*k-1)-(j*k+z)],ll[a][((md+1)*k-1)-e.first]+e.second);
                }
            }
        }
    }
    for(int j = md+1;j<=r;j++){
        for(int z = 0;z<k;z++){
            for(int a = 0;a<k;a++){
                if(j==md+1){
                    if(z==a)rr[a][(j*k+z)-((md+1)*k)] = 0;
                    else rr[a][(j*k+z)-((md+1)*k)] = 1e9;
                    continue;
                }
                rr[a][(j*k+z)-((md+1)*k)] = 1e9;
                for(auto e:rev[j*k+z]){
                    rr[a][(j*k+z)-((md+1)*k)] = min(rr[a][(j*k+z)-((md+1)*k)],rr[a][e.first-((md+1)*k)]+e.second);
                }
            }
        }
    }
    vector<pair<pair<int,int>,int>> R,L;
    for(auto i:qu){
        if(i.first.first/k>md){
            R.push_back(i);
        }else if(i.first.second/k<md){
            L.push_back(i);
        }else{
            if((i.first.second/k)==md){
                an[i.second] = ll[i.first.second%k][((md+1)*k-1)-i.first.first];
            }else{
                long long ans = 1e18;
                for(int z = 0;z<k;z++){
                    for(int e = 0;e<k;e++){
                        ans = min(ans,ll[z][((md+1)*k-1)-i.first.first]+rr[e][i.first.second-((md+1)*k)]+(mp.count(make_pair((md*k)+z,(md+1)*k+e))==0?1000000000:mp[{(md*k)+z,(md+1)*k+e}]));
                    }
                }
                an[i.second] = ans;
            }
        }
    }
    dc(l,md-1,L);dc(md+1,r,R);
}
int main(){
    memset(an,-1,sizeof an);
    int n,m,o;
    cin>>k>>n>>m>>o;
    for(int i = 0;i<m;i++){
        long long a,b,c;
        cin>>a>>b>>c;
        mp[{a,b}] = c;
        adj[a].push_back({b,c});
        rev[b].push_back({a,c});
    }
    vector<pair<pair<int,int>,int>> qu;
    for(int i = 0;i<o;i++){
        long long a,b;cin>>a>>b;
        if(a==b){
            an[i] = 0;continue;
        }
        qu.push_back({{a,b},i});
    }
    dc(0,(n-1)/k,qu);
    for(int i = 0;i<o;i++){
        cout<<(an[i]>=1e9?-1:an[i])<<endl;
    }
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 31 / 31
• Subtask 5: 44 / 44