Submission #695185

#	Time	Username	Problem	Language	Result	Execution time	Memory
695185		HossamHero7	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	36 / 100	1107 ms	239568 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
#define endl '\n'
vector<int> adj[2000];
bitset<30000> vis[2000];
bitset<2000> vis2;
int dis[2000][30000];
void solve(){
    int n,m;
    cin>>n>>m;
    vector<pair<int,int>> v(m);
    int pos = 0;
    for(int i=0;i<m;i++){
        int a,b;cin>>a>>b;
        v[i].first = a;
        v[i].second = b;
        if(i == 1) pos = a;
        adj[a].push_back(i);
    }
    queue<pair<int,int>> q;
    q.push({v[0].first,0});
    while(q.size()){
        pair<int,int> cur = q.front();     q.pop();
        if(!vis2[cur.first]){
            for(auto ch : adj[cur.first]){
                int p = v[ch].second;
                if(cur.first+p<n && !vis[cur.first+p][ch]){
                    q.push({cur.first+p,ch});
                    dis[cur.first+p][ch] = dis[cur.first][cur.second] + 1;
                    vis[cur.first+p][ch] = 1;
                }
                if(cur.first-p>=0 && !vis[cur.first-p][ch]){
                    q.push({cur.first-p,ch});
                    dis[cur.first-p][ch] = dis[cur.first][cur.second] + 1;
                    vis[cur.first-p][ch] = 1;
                }
            }
        }

        vis2[cur.first] = 1;
        int p = v[cur.second].second;
        if(cur.first+p<n && !vis[cur.first+p][cur.second]){
            q.push({cur.first+p,cur.second});
            dis[cur.first+p][cur.second] = dis[cur.first][cur.second] + 1;
            vis[cur.first+p][cur.second] = 1;
        }
        if(cur.first-p>=0 && !vis[cur.first-p][cur.second]){
            q.push({cur.first-p,cur.second});
            dis[cur.first-p][cur.second] = dis[cur.first][cur.second] + 1;
            vis[cur.first-p][cur.second] = 1;
        }
    }
    if(v[0].first == v[1].first){
        cout<<0<<endl;
    }
    else {
        int ans = 1e9;
        for(int i=0;i<m;i++){
            if(i == 1) continue;
            if(dis[v[1].first][i] == 0) continue;
            ans = min(ans,dis[v[1].first][i]);
        }
        cout<<(ans==1e9?-1:ans)<<endl;
    }
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);      cout.tie(0);
    int t=1;
    // cin>>t;
    while(t--){
        solve();
    }
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void solve()':
skyscraper.cpp:14:9: warning: variable 'pos' set but not used [-Wunused-but-set-variable]
   14 |     int pos = 0;
      |         ^~~

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