Submission #866893

#	Time	Username	Problem	Language	Result	Execution time	Memory
866893		1075508020060209tc	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	72 ms	9936 KiB

skyscraper

#pragma GCC optimize ("O3")
#include<bits/stdc++.h>
using namespace std;
//#define int long long
int n;int m;
int dis[30100];
vector<int>e[30100];
set<int>st[30100];
int vis[30100];
int ar[30100];
int br[30100];
int frm[30100];
signed main(){
cin.tie(0);
ios_base::sync_with_stdio(0);
cin>>n>>m;
for(int i=0;i<m;i++){
    cin>>ar[i]>>br[i];
    st[ar[i]].insert(br[i]);
//    e[ar[i]].push_back(br[i]);
}
for(int i=0;i<n;i++){
    for(auto it=st[i].begin();it!=st[i].end();it++){
        e[i].push_back(*it);
    }
}

for(int i=0;i<n;i++){
    dis[i]=2000000000;
}
dis[ar[0]]=0;

priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>pq;
pq.push({0,ar[0]});

while(pq.size()){
    int nw=pq.top().second;
    pq.pop();
    if(vis[nw]){continue;}
    vis[nw]=1;
//    lft.erase(nw);
    if(nw==ar[1]){
        cout<<dis[nw]<<"\n";return 0;
    }
    for(int i=0;i<e[nw].size();i++){
        int d=e[nw][i];
        if(d==frm[nw]){continue;}
        int v=nw+d;int t=1;
        for(;v<n;){
            //int v=nw+t*d;
//            dis[v]=min(dis[v],dis[nw]+t);
            if(dis[v]>dis[nw]+t){
                dis[v]=dis[nw]+t;
                frm[v]=d;
                pq.push({dis[v],v});
            }

            v+=d;t++;
        }
        v=nw-d;t=1;
        for(;v>=0;){
            if(dis[v]>dis[nw]+t){
                dis[v]=dis[nw]+t;
                frm[v]=d;
                pq.push({dis[v],v});
            }
            v-=d;t++;
        }
    }
}
if(dis[ar[1]]>1000000000){
    cout<<-1<<endl;
    return 0;
}
cout<<dis[ar[1]]<<endl;

}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:45:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |     for(int i=0;i<e[nw].size();i++){
      |                 ~^~~~~~~~~~~~~

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