Submission #597160

#	Time	Username	Problem	Language	Result	Execution time	Memory
597160		slime	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	325 ms	262144 KiB

skyscraper

#include "bits/stdc++.h"
using namespace std;
const int MAXN = 4e6 + 10;
const int MOD = 1e9 + 7;
#define ll __int128
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;
}
ll read() { int x; cin >> x; return (ll)x; }
long long bm(long long b, long long p) {
  if(p==0) return 1 % MOD;
  long long r = bm(b, p >> 1);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
long long inv(long long b) { 
  return bm(b, MOD-2);
}
long long f[MAXN];
long long nCr(int n, int r) { 
  long long ans = f[n]; ans *= inv(f[r]); ans %= MOD;
  ans *= inv(f[n-r]); ans %= MOD; return ans;
}
long long fib[MAXN], lucas[MAXN];
void precomp() { 
  for(int i=0; i<MAXN; i++) f[i] = (i == 0 ? 1 % MOD : (f[i-1] * i) % MOD); 
  lucas[0] = 2;
  lucas[1] = 1;
  for(int i=2; i<MAXN; i++) lucas[i] = (lucas[i-2] + lucas[i-1]) % MOD;
  fib[0] = 0;
  fib[1] = 1;
  for(int i=2; i<MAXN; i++) fib[i] = (fib[i-2] + fib[i-1]) % MOD;
}
int fastlog(int x) {
  return (x == 0 ? -1 : 64 - __builtin_clzll(x) - 1);
}
void gay(int i) { cout << "Case #" << i << ": "; }
int csb(int l, int r, int k) { // count number of [l, r] such that i & 2^k > 0
  if(l > r) return 0;
  if(l == 0) {
    int s = r / (1ll << (k+1)); // number of complete cycles
    int t = r % (1ll << (k+1));
    int ans = s * (1ll << k);
    ans += (t >= (1ll << k) ? t - (1ll << k) + 1 : 0);
    return ans;
  }
  else return csb(0, r, k) - csb(0, l - 1, k);
}
int lis(vector<int> a) {
  int n = a.size();
  int bucket[n+1];
  for(int i=1; i<=n; i++) bucket[i] = 1e18;
  int ans = 1;
  for(int x: a) {
    auto it = lower_bound(bucket + 1, bucket +n +1, x);
    int d = distance(bucket, it);
    ans = max(ans, d);
    bucket[d] = min(bucket[d], x);
  }
  return ans;
}
vector<pair<int, short> > adj[MAXN];
void solve(int tc) {
  int n, m;
  cin >> n >> m;
  int nxt = n;
  int sq = ceil(sqrt(n));
  int link[n][sq];
  for(int i=1; i<sq; i++) {
    
    for(int j=0; j<i; j++) {
      for(int k=j; k<n; k+=i) {
        link[k][i] = nxt;
        nxt++;
      }
      for(int k=j; k<n; k+=i) {
        if(k+i < n) {
          adj[link[k][i]].push_back({link[k+i][i], 1});
          adj[link[k+i][i]].push_back({link[k][i], 1});
        }
        adj[link[k][i]].push_back({k, 0});
      }
    }
  }
  int st, en;
  for(int i=0; i<m; i++) {
    //cout << "i = " << i << "\n";
    int b, p;
    cin >> b >> p;
    if(i == 0) st = b;
    else if(i == 1) en = b;
    
    if(p >= sq) {
      for(int j=b%p; j<n; j+=p) {
        link[j][0] = nxt;
        nxt++;
      }
      for(int j=b%p; j<n; j+=p) {
        if(j+p < n) {
          adj[link[j][0]].push_back({link[j+p][0], 1});
          adj[link[j+p][0]].push_back({link[j][0], 1});
        }
        adj[link[j][0]].push_back({j, 0});
      }
      adj[b].push_back({link[b][0], 0});
    }
    else {
      adj[b].push_back({link[b][p], 0});
    }
  }
 
  priority_queue<pair<int, int>,vector<pair<int, int> >,greater<pair<int, int> > > pq;
  
  int dist[nxt];
  
  bool vis[nxt];
  for(int i=0; i<nxt; i++) vis[i] = 0, dist[i] = 1e9;
  dist[st] = 0;
  pq.push({0, st});
  while(pq.size()) {
    pair<int, int> t = pq.top(); pq.pop();
    if(!vis[t.second]) {
      vis[t.second] = 1;
      for(pair<int, int> x: adj[t.second]) {
        if(!vis[x.first] && dist[x.first] > dist[t.second] + x.second) {
          dist[x.first] = dist[t.second] + x.second;
          pq.push({dist[x.first], x.first});
        }
      }
    }
  }
  cout << (dist[en] == 1e9 ? -1 : dist[en]) << "\n";
}
int32_t main() {
  precomp();
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
}
// I don't know geometry.
// Teaming is unfair.

Compilation message (stderr)

skyscraper.cpp: In function 'int lis(std::vector<int>)':
skyscraper.cpp:53:39: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   53 |   for(int i=1; i<=n; i++) bucket[i] = 1e18;
      |                                       ^~~~
skyscraper.cpp: In function 'void solve(int)':
skyscraper.cpp:133:19: warning: 'en' may be used uninitialized in this function [-Wmaybe-uninitialized]
  133 |   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