Submission #972743

#	Time	Username	Problem	Language	Result	Execution time	Memory
972743		Gangsta	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	222 ms	64924 KiB

skyscraper

#include "bits/stdc++.h"
#define ll long long int
#define pb push_back
#define pii pair<int,int>
#define ff first
#define ss second
#define sz size()

const int N = 3e4 + 5;

using namespace std;

int n, m, b[N], p[N];

vector <pii> v[N];

priority_queue <pii> pq;

vector <int> dis(N,1e9), q[N];

map <pii,int> mp;

void f(){
    pq.push({0,b[1]});
    dis[b[1]] = 0;
    while(!pq.empty()){
        int a = pq.top().ss;
        pq.pop();
        for(auto i: v[a]){
            if(dis[a] + i.ss < dis[i.ff]){
                dis[i.ff] = dis[a] + i.ss;
                pq.push({-dis[i.ff],i.ff});
            }
        }
    }
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    //freopen("input.in", "r", stdin);
    //freopen("output.out", "w", stdout);
    cin >> n >> m;
    for(int i = 1; i <= m; i++){
        cin >> b[i] >> p[i];
        if(mp.find({b[i],p[i]}) == mp.end()){
            mp[{b[i],p[i]}] = 1;
            q[b[i]].pb(p[i]);
        }
    }
    for(int i = 0; i < n; i++){
        for(auto j: q[i]){
            int nd = i, cnt = 0;
            while(1){
                nd -= j;
                if(nd < 0) break;
                cnt++;
                v[i].pb({nd,cnt});
                if(mp.find({nd,j}) != mp.end()) break;
            }
            nd = i, cnt = 0;
            while(1){
                nd += j;
                if(nd > n-1) break;
                cnt++;
                v[i].pb({nd,cnt});
                if(mp.find({nd,j}) != mp.end()) break;
            }
        }
    }
    f();
    cout << (dis[b[2]] == 1e9 ? -1 : dis[b[2]]);
}

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