Submission #167485

#	Time	Username	Problem	Language	Result	Execution time	Memory
167485		muhammad_hokimiyon	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	461 ms	131756 KiB

skyscraper

#include <bits/stdc++.h>

//#pragma GCC optimize("Ofast")

#define fi first
#define se second
#define ll long long

using namespace std;

const int N = 1e6 + 7;
const int mod = 1e9 + 7;

int n,m;
int a[N];
int b[N];
int d[N];
int h[N];
int t[N];
set < int > s[N];
vector < pair < int , int > > v[N];

void solve()
{
    cin >> n >> m;
    for( int i = 0; i < m; i++ ){
        cin >> a[i] >> b[i];
        s[a[i]].insert(b[i]);
    }
    for( int i = 0; i <= n; i++ )d[i] = 1e9;
    for( int i = 0; i < n; i++ ){
        auto it = s[i].begin();
        while( it != s[i].end() ){
            int z = i , cnt = 0;
            while( z + *it < n ){
                z += *it , cnt++;
                v[i].push_back({z , cnt});
                if( s[z].find(*it) != s[z].end() )break;
            }
            z = i , cnt = 0;
            while( z - *it >= 0 ){
                z -= *it , cnt++;
                v[i].push_back({z , cnt});
                if( s[z].find(*it) != s[z].end() )break;
            }
            it++;
        }
    }
    d[a[0]] = 0;
    set < pair < int , int > > q;
    q.insert({0 , a[0]});
    while( !q.empty() ){
        int x = q.begin()->se;
        q.erase(q.begin());
        for( auto y : v[x] ){
            if( d[x] + y.se < d[y.fi] ){
                q.erase({d[y.fi] , y.fi});
                d[y.fi] = d[x] + y.se;
                q.insert({ d[y.fi] , y.fi });
            }
        }
    }
    if( d[a[1]] == 1e9 )d[a[1]] = -1;
    cout << d[a[1]];
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen( "input.txt" , "r" , stdin );
    //freopen( "output.txt" , "w" , stdout );

    int t = 1;//cin >> t;
    while( t-- ){
        solve();
    }
}

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