Submission #132198

#	Time	Username	Problem	Language	Result	Execution time	Memory
132198		shafinalam	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	595 ms	262148 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;
const int mxn = 3e4+5;
typedef pair<int,int>pii;
vector<pii>adj[mxn];
vector<pii>tmp;
int dis[mxn];
int n, m;
int dijkstra(int src, int des)
{
    priority_queue<pii, vector<pii>, greater<pii> >pq;
    for(int i = 0; i < n; i++) dis[i] = 999999999;
    dis[src] = 0;
    pq.push(make_pair(0, src));

    while(!pq.empty())
    {
        pii cur = pq.top();
        int u = cur.second;
        int cost = cur.first;
        pq.pop();
        for(pii x : adj[u])
        {
            int v = x.first;
            int w = x.second;
            if(dis[v]>w+cost)
            {
                dis[v] = w+cost;
                pq.push(make_pair(dis[v], v));
            }
        }
    }
    return dis[des];
}
int main()
{
    scanf("%d%d", &n, &m);

    int src, des;
    for(int i = 0; i < m; i++)
    {
        int b, p;
        scanf("%d%d", &b, &p);
        if(i==0) src = b;
        if(i==1) des = b;
        tmp.push_back(make_pair(b, p));
    }
    sort(tmp.begin(), tmp.end());
    tmp.erase(unique(tmp.begin(), tmp.end()), tmp.end());
    for(int i = 0; i < tmp.size(); i++)
    {
        int b = tmp[i].first;
        int p = tmp[i].second;

        int x = b+p, k = 1;
        while(x<n)
        {
            adj[b].push_back(make_pair(x, k));
            x+=p;
            k++;
        }
        x = b-p, k = 1;
        while(x>=0)
        {
            adj[b].push_back(make_pair(x, k));
            x-=p;
            k++;
        }
    }
    int ans = dijkstra(src, des);
    if(ans==999999999) cout << -1 << '\n';
    else cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:51:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < tmp.size(); i++)
                    ~~^~~~~~~~~~~~
skyscraper.cpp:38:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:44:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &b, &p);
         ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:71:32: warning: 'des' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int ans = dijkstra(src, des);
                                ^
skyscraper.cpp:71:32: warning: 'src' may be used uninitialized in this function [-Wmaybe-uninitialized]

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