Submission #238139

#	Time	Username	Problem	Language	Result	Execution time	Memory
238139		Mercenary	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	22 / 100	9 ms	3456 KiB

skyscraper

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/trie_policy.hpp>

#define pb push_back
#define mp make_pair
#define taskname "SKY"

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef tree <int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;

const int maxn = 5e4 + 5;
const int mod = 1e9 + 7;
int dis[maxn] , n , m;
unordered_set<int> s[maxn];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen(taskname".INP","r")){
		freopen(taskname".INP", "r",stdin);
		freopen(taskname".OUT", "w",stdout);
    }
    cin >> n >> m;
    int ft = 0 , lt = 0;
    for(int i = 0 ; i < m ; ++i){
        int u ,v;cin >> u >> v;s[u].insert(v);
        if(i == 0)ft = u;
        if(i == 1)lt = u;
    }
    priority_queue<ii , vector<ii> , greater<ii> > pq;
    fill_n(dis,maxn,1e9);
    dis[ft] = 0;pq.push(mp(0,ft));
    while(pq.size()){
        auto u = pq.top();pq.pop();
        if(dis[u.second] != u.first)continue;
        for(auto &c : s[u.second]){
            int cnt = 0;
            for(int i = u.second + c ; i < n ; i += c){
                cnt++;
                if(u.first + cnt < dis[i]){
                    dis[i] = u.first + cnt;pq.push(mp(dis[i],i));
                }
                if(s[i].count(c))break;
            }
            cnt = 0;
            for(int i = u.second - c ; i > 0 ; i -= c){
                cnt++;
                if(u.first + cnt < dis[i]){
                    dis[i] = u.first + cnt;pq.push(mp(dis[i],i));
                }
                if(s[i].count(c))break;
            }
        }
    }
    if(dis[lt] == 1e9)cout << -1;
    else cout << dis[lt];
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:27:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen(taskname".INP", "r",stdin);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:28:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen(taskname".OUT", "w",stdout);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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