Submission #1097790

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097790		KasymK	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	328 ms	13768 KiB

skyscraper

#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define tr(i, c) for(auto i = c.begin(); i != c.end(); ++i)
#define wr puts("----------------")
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N = 3e4+5;
const ll INF = 1e18;
set<int> adj[N];
ll dis[N];
 
int main(){
    int n, m, s, t;
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= m; ++i){
        int x, p;
        scanf("%d%d", &x, &p), x++;
        if(i == 1)
            s = x;
        if(i == 2)
            t = x;
        adj[x].insert(p);
    }
    for(int i = 1; i <= n; ++i)
        dis[i] = INF;
    priority_queue<pli, vector<pli>, greater<pli>> pq;
    pq.push({0, s});
    dis[s] = 0;
    while(!pq.empty()){
        pli P = pq.top();
        pq.pop();
        ll val = P.ff;
        int x = P.ss;
        if(dis[x] != val)
            continue;
        for(int p : adj[x]){
            for(int i = 1; x-i*p >= 1; ++i){
                int to = x-i*p;
                if(umin(dis[to], val+i))
                    pq.push({dis[to], to});
            }
            for(int i = 1; x+i*p <= n; ++i){
                int to = x+i*p;
                if(umin(dis[to], val+i))
                    pq.push({dis[to], to});
            }
        }
    }
    int d = -1;
    printf("%lld\n", dis[t]==INF?d:dis[t]);
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:22:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |         scanf("%d%d", &x, &p), x++;
      |         ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:36:12: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
   36 |     dis[s] = 0;
      |     ~~~~~~~^~~
skyscraper.cpp:58:27: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
   58 |     printf("%lld\n", dis[t]==INF?d:dis[t]);
      |                      ~~~~~^

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