Submission #45851

#	Time	Username	Problem	Language	Result	Execution time	Memory
45851		antimirage	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	0 / 100	15 ms	16492 KiB

skyscraper

#include <bits/stdc++.h>

#define fr first
#define sc second
#define mk make_pair
#define pb push_back
#define OK puts("OK");
#define sz(s) (int)s.size()
#define all(s) s.begin(), s.end()

using namespace std;

const int N = 2005, inf = 1e9 + 7;

int n, m, u[N][N], pos[N], pw[N], ans = 1e9 + 7;

vector <int> vec[N];

priority_queue < pair < int, pair <int, int> > > q;

main()
{
    cin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        scanf("%d%d", &pos[i], &pw[i]);
        vec[pos[i]].pb(pw[i]);
    }
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
            u[i][j] = inf;

    for (auto to : vec[ pos[0] ])
    {
        if (u[ pos[0] ][to] > 0)
        {
            q.push( mk( 0, mk(pos[0], to) ) );
            u[ pos[0] ][to] = 0;
        }
    }
    vec[ pos[0] ].clear();

    while (!q.empty() )
    {
        int v = q.top().sc.fr, cur_pow = q.top().sc.sc, cur_len = -q.top().fr;
        q.pop();

        if ( cur_len > u[v][cur_pow] ) continue;

        for (auto it : vec[v])
        {
            if (u[v][it] > u[v][cur_pow])
            {
                u[v][it] = u[v][cur_pow];
                q.push( mk(-u[v][it], mk(v, it) ) );
            }
        }
        vec[v].clear();

        if ( v - cur_pow >= 0 && u[v - cur_pow][cur_pow] > u[v][cur_pow] + 1 )
        {
            u[v - cur_pow][cur_pow] = u[v][cur_pow] + 1;
            q.push( mk(-u[v - cur_pow][cur_pow], mk(v - cur_pow, cur_pow) ) );
        }
        if ( v + cur_pow < n && u[v + cur_pow][cur_pow] > u[v][cur_pow] + 1 )
        {
            u[v + cur_pow][cur_pow] = u[v][cur_pow] + 1;

            q.push( mk( -u[v + cur_pow][cur_pow], mk(v + cur_pow, cur_pow) ) );
        }
    }
    for (int i = 0; i < m; i++)
        ans = min(ans, u[ pos[1] ][i] );

    if (ans == inf)
        ans = -1;

    cout << ans << endl;
}
/**
5 3
0 2
1 1
4 1
**/

Compilation message (stderr)

skyscraper.cpp:21:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:26:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &pos[i], &pw[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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