Submission #1187287

#	Time	Username	Problem	Language	Result	Execution time	Memory
1187287		Warinchai	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	57 / 100	193 ms	263764 KiB

skyscraper

#include<bits/stdc++.h>
using namespace std;
map<pair<short,short>,vector<short>>mp;
vector<pair<int,bool>>adj[5000005];
vector<int>dis;
int inf=1e9;
int have[30005];
int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n,m;cin>>n>>m;
    int st=0,en=0;
    for(int i=0;i<m;i++){
        int b,p;cin>>b>>p;
        if(i==0)st=b;
        if(i==1)en=b;
        if(i!=1)mp[{b%p,p}].push_back(b);
        have[b]++;
    }
    int id=n-1;
    for(auto x:mp){
        int cur=x.first.first;
        int p=x.first.second;
        for(auto b:x.second)adj[b].push_back({id+(b-cur)/p+1,0});
        for(cur;cur<n;cur+=p){
            id++;
            if(have[cur])adj[id].push_back({cur,0});
            if(cur!=x.first.first)adj[id-1].push_back({id,1});
        }
        cur=x.first.first;
        for(auto b:x.second)adj[b].push_back({id+(b-cur)/p+1,0});
        for(cur;cur<n;cur+=p){
            id++;
            if(have[cur])adj[id].push_back({cur,0});
            if(cur!=x.first.first)adj[id].push_back({id-1,1});
        }
    }
    assert(id<2e6);
    dis.resize(id+1,inf);
    mp.clear();
    deque<pair<int,int>>dq;
    dq.push_back({0,st});
    while(!dq.empty()){
        auto [d,u]=dq.front();
        assert(u<2e6);
        dq.pop_front();
        if(d>=dis[u])continue;
        dis[u]=d;
        assert(u<2e6);
        if(u==en)break;
        for(auto v:adj[u]){
            assert(v.first<2e6);
            if(v.second+d>=dis[v.first])continue;
            if(v.second)dq.push_back({d+1,v.first});
            else dq.push_front({d,v.first});
        }
    }
    if(dis[en]==inf)cout<<-1;
    else cout<<dis[en];
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 0 / 43