Submission #108886

#	Time	Username	Problem	Language	Result	Execution time	Memory
108886		kuroni	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	210 ms	79140 KiB

skyscraper

#include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <algorithm>
#define fi first
#define se second
using namespace std;
    
const int N = 30005, D = 180, MX = 5E5 + 5, INF = 1E9 + 7;
    
int n, m, d, b, p, st, en, dis[N][D];
vector<int> dif[N];
vector<pair<int, int>> ve[MX];
    
void mini(pair<int, int> u, int v)
{
    if (dis[u.fi][u.se] > v)
    {
        dis[u.fi][u.se] = v;
        ve[v].push_back(u);
    }
}
    
void dijkstra()
{
    for (int i = 0; i < n; i++)
        for (int j = 0; j < d; j++)
            dis[i][j] = INF;
    dis[st][0] = 0; ve[0].push_back({st, 0});
    for (int i = 0; i < MX; i++)
        while (!ve[i].empty())
        {
            pair<int, int> u = ve[i].back(); ve[i].pop_back();
            if (u.se == 0)
            {
                for (int &v : dif[u.fi])
                {
                    if (v < d)
                        mini({u.fi, v}, i);
                    else
                        for (int j = u.fi % v; j < n; j += v)
                            mini({j, 0}, i + abs(u.fi - j) / v);
                }
            }
            else
            {
                mini({u.fi, 0}, i);
                if (u.fi + u.se < n)
                    mini({u.fi + u.se, u.se}, i + 1);
                if (u.fi - u.se >= 0)
                    mini({u.fi - u.se, u.se}, i + 1);
            }
        }
    printf("%d\n", dis[en][0] == INF ? -1 : dis[en][0]);
}
    
int main()
{
    scanf("%d%d", &n, &m);
    d = sqrt(n - 1) + 1;
    for (int i = 0; i < m; i++)
    {
        scanf("%d%d", &b, &p);
        if (i == 0)
            st = b;
        else if (i == 1)
            en = b;
        dif[b].push_back(p);
    }
    for (int i = 0; i < n; i++)
    {
        sort(dif[i].begin(), dif[i].end());
        dif[i].erase(unique(dif[i].begin(), dif[i].end()), dif[i].end());
    }
    dijkstra();
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:60:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:64:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &b, &p);
         ~~~~~^~~~~~~~~~~~~~~~

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