Submission #826531

#	Time	Username	Problem	Language	Result	Execution time	Memory
826531		cig32	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	180 ms	262144 KiB

skyscraper

#include "bits/stdc++.h"
using namespace std;
#define double long double
const int MAXN = 9500000;
const int MOD = 1e9 + 7;
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
int bm(int b, int p) {
  if(p==0) return 1 % MOD;
  int r = bm(b, p >> 1);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
int inv(int b) { 
  return bm(b, MOD-2);
}
int fastlog(int x) {
  return (x == 0 ? -1 : 64 - __builtin_clzll(x) - 1);
}
void printcase(int i) { cout << "Case #" << i << ": "; }
vector<int>adj[MAXN];
void solve(int tc) {
  int n, m;
  cin >> n >> m;
  int s = sqrt(n);
  int nxt = (s+1) * n;
  for(int i=1; i<=s; i++) {
    for(int j=i*n; j<(i+1)*n; j++) {
      if(j+i < (i+1)*n) adj[j].push_back((j+i) * 2 + 1);
      if(j-i >= i*n) adj[j].push_back((j-i) * 2 + 1);
      adj[j].push_back((j%n) * 2 + 0);
    }
  }
  int st, en;
  for(int i=0; i<m; i++) {
    int b, p;
    cin >> b >> p;
    if(i == 0) st = b;
    if(i == 1) en = b;
    if(p <= s) adj[b].push_back((b+p*n) * 2 + 0);
    else {
      for(int j=b%p; j<n; j+=p) {
        if(j+p < n) adj[nxt + j/p].push_back((nxt + j/p + 1) * 2 + 1);
        if(j-p >= 0) adj[nxt + j/p].push_back((nxt + j/p - 1) * 2 + 1);
        adj[nxt + j/p].push_back(j * 2 + 0);
      }
      adj[b].push_back((nxt + b/p) * 2 + 0);
      for(int j=b%p; j<n; j+=p) {
        nxt++;
      }
    }
  }
  int k = nxt;
  int dist[k];
  bool vis[k];
  for(int i=0; i<k; i++) dist[i] = 1e9, vis[i] = 0;
  dist[st] = 0;
  deque<int> dq;
  dq.push_back(st);
  while(dq.size()) {
    int f = dq.front();
    dq.pop_front();
    if(!vis[f]) {
      vis[f] = 1;
      for(int x: adj[f]) {
        if(!vis[x / 2] && dist[x / 2] > dist[f] + (x % 2)) {
          dist[x / 2] = dist[f] + (x % 2);
          if(x % 2 == 0) dq.push_front(x / 2);
          else dq.push_back(x / 2);
        }
      }
    }
  }
  cout<<(dist[en]==1e9?-1:dist[en])<<"\n";
}
int32_t main() {
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
}
// 勿忘初衷

Compilation message (stderr)

skyscraper.cpp: In function 'void solve(int)':
skyscraper.cpp:76:17: warning: 'en' may be used uninitialized in this function [-Wmaybe-uninitialized]
   76 |   cout<<(dist[en]==1e9?-1:dist[en])<<"\n";
      |          ~~~~~~~^

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