Submission #96919

#	Time	Username	Problem	Language	Result	Execution time	Memory
96919		MohamedAhmed0	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	22 / 100	8 ms	2944 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

const int MAX = 30010 ;
vector< vector< pair<int , int> > >adj(MAX) ;
vector< set<int , greater<int> > >place(MAX) ;
int dist[MAX] ;

int main()
{
    for(int i = 1 ; i <= 30000 ; ++i)
        dist[i] = 2e9 ;
    int n , m ;
    scanf("%d %d" , &n , &m) ;
    int s , e ;
    for(int i = 0 ; i < m ; ++i)
    {
        int x , y ;
        cin>>x>>y ;
        if(i == 0)
            s = x ;
        if(i == 1)
            e = x ;
        place[x].insert(y) ;
    }
    for(int i = 0 ; i < n ; ++i)
    {
        for(auto &x : place[i])
        {
            for(int j = 1 ; ; ++j)
            {
                int now = i + j * x ;
                if(now >= n)
                    break;
                adj[i].emplace_back(now , j) ;
                if(place[now].count(j))
                    break;
            }
            for(int j = 1 ; ; ++j)
            {
                int now = i - j * x ;
                if(now < 0)
                    break ;
                adj[i].emplace_back(now , j) ;
                if(place[now].count(j))
                    break;
            }
        }
    }
    priority_queue< pair<int , int> , vector< pair<int , int> > , greater< pair<int,  int> > >q ;
    q.push({0 , s}) ;
    dist[s] = 0 ;
    while(!q.empty())
    {
        pair<int , int>p = q.top();
        q.pop();
        int d = p.first , now = p.second ;
        if(d > dist[now])
            continue;
        if(now == e)
            return cout<<d<<"\n" , 0 ;
        dist[now] = 2 ;
        for(auto &i : adj[now])
        {
            int to = i.first ;
            int distto = i.second + d ;
            if(distto < dist[to])
            {
                dist[to] = distto ;
                q.push({distto , to}) ;
            }
        }
    }
    return cout<<-1<<"\n" , 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d" , &n , &m) ;
     ~~~~~^~~~~~~~~~~~~~~~~~~
skyscraper.cpp:53:13: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
     dist[s] = 0 ;
     ~~~~~~~~^~~
skyscraper.cpp:61:9: warning: 'e' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if(now == e)
         ^~

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