Submission #1032744

#	Time	Username	Problem	Language	Result	Execution time	Memory
1032744		Phuoc	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	614 ms	3800 KiB

skyscraper

#include <bits/stdc++.h>
#include <iostream>
#include <cmath>
#include <iomanip>
#include <vector>
#include <map>
#include <stack>
#include <queue>
 
using namespace std;
 
#define ll long long
#define pb push_back
#define el '\n'
#define mpair make_pair
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1)
#define fi first
#define se second
 
/* Author: Pham Gia Phuoc */
 
const ll MOD = (ll)(1e9) + 1LL * 19972207;
 
template <class T1, class T2>
    void add(T1 &a, T2 b){
        a += b;
        if(a >= MOD) a -= MOD;
    }
 
template <class T1, class T2>
    void sub(T1 &a, T2 b){
        a -= b;
        if(a < 0) a += MOD;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if(a > b){a = b; return true;} return false;
    }
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if(a < b){a = b; return true;} return false;
    }
 
/** END OF TEMPLATE. DRINK A CUP OF COFFEE BEFORE READING MY CODE **/
 
const int MAX = 30010;
const ll INF = (ll) 1e18 + 67LL;
const int oo = (int)(1e9 + 7);
const int NUM_BIT = 62;

int N, M;
vector <int> adj[MAX];
int S, T;
 
void init(){
    cin >> N >> M;
    for(int i = 0; i < M; i++){
        int a, b; cin >> a >> b;
        adj[a].push_back(b);
        if(i == 0) S = a;
        if(i == 1) T = a;
    }
}

int dist[MAX];
bool vis[MAX];

int dijkstra(int s, int t){
    memset(dist, 0x3f, sizeof dist);
    memset(vis, 0, sizeof vis);
    dist[s] = 0;
    priority_queue <pair <int, int>, vector <pair <int, int> >, greater <pair <int, int> > > pq;
    #define PUSH(u) pq.push(make_pair(dist[u], u))
    PUSH(s);

    while(!pq.empty()){
        int du = pq.top().fi;
        int u = pq.top().se;
        pq.pop();
        
        if(!vis[u]){
            vis[u] = 1;
            for(int p:adj[u]){
                for(int i = 1; u + i * p < N; i++){
                    int v = u + i * p; 
                    if(minimize(dist[v], dist[u] + i)) PUSH(v);
                }

                for(int i = -1; u + i * p >= 0; i--){
                    int v = u + i * p;
                    if(minimize(dist[v], dist[u] + abs(i))) PUSH(v);
                }
            }
        }
    }

    return dist[t];
}

void solve(){
    int ans = dijkstra(S, T);
    // int ans = 0;
    if(ans >= oo) cout << -1;
    else cout << ans;
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #define test "test"
    srand(time(0));
    int t = 1;
    while(t--){
        // gen();
        init();
        solve();
    }
    
    return 0;
}
 
 
 
/*** ROAD TO VOI 2025 ***/

Compilation message (stderr)

skyscraper.cpp: In function 'int dijkstra(int, int)':
skyscraper.cpp:80:13: warning: unused variable 'du' [-Wunused-variable]
   80 |         int du = pq.top().fi;
      |             ^~

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