Submission #705537

#	Time	Username	Problem	Language	Result	Execution time	Memory
705537		Alihan_8	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	187 ms	125992 KiB

skyscraper

#include <bits/stdc++.h>
// include <ext/pb_ds/assoc_container.hpp>
// include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
using namespace std;
#define all(x) x.begin(), x.end()
#define pb push_back
// define ordered_set tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>
#define mpr make_pair
#define ln '\n'
void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
#define int long long
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, m; cin >> n >> m;
    set <int> S[n];
    int en = -1, st = -1;
    for ( int i = 1; i <= m; i++ ){
        int pos, val; cin >> pos >> val;
        if ( i == 1 ) st = pos;
        if ( i == 2 ) en = pos;
        S[pos].insert(val);
    }
    vector <pair<int,int>> g[n];
    for ( int i = 0; i < n; i++ ){
        for ( auto val: S[i] ){
            int cnt = 0;
            for ( int j = i+val; j < n; j += val ){
                g[i].pb({j, ++cnt});
                if ( S[j].count(val) ) break;
            } cnt = 0;
            for ( int j = i-val; j >= 0; j -= val ){
                g[i].pb({j, ++cnt});
                if ( S[j].count(val) ) break;
            }
        }
    }
    const int inf = 1e16;
    vector <int> dis(n, 1e16);
    priority_queue <pair<int,int>> q;
    dis[st] = 0;
    q.push({0, st});
    while ( !q.empty() ){
        auto [val, cur] = q.top();
        q.pop(); val = -val;
        if ( val > dis[cur] ) continue;
        for ( auto [to, w]: g[cur] ){
            int new_dis = val+w;
            if ( new_dis < dis[to] ){
                dis[to] = new_dis;
                q.push({-dis[to], to});
            }
        }
    }
    if ( dis[en] == inf ) dis[en] = -1;
    cout << dis[en];

    cout << '\n';
}
/*
5 3
0 2
1 1
4 1
*/

Compilation message (stderr)

skyscraper.cpp: In function 'void IO(std::string)':
skyscraper.cpp:11:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:11:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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