Submission #549053

#	Time	Username	Problem	Language	Result	Execution time	Memory
549053		czhang2718	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	434 ms	168044 KiB

skyscraper

#include "bits/stdc++.h"
using namespace std;

typedef pair<int,int> pii;
#define f first
#define s second
#define nl '\n'
#define pb push_back
#define sz(x) (int) x.size()

const int N=30001;
const int B=175;
const int MX=5000000;
short n,m;
vector<short> v[N];
short P[N], x[N];
int dist[N][B];
bool done[N][B];
vector<pair<short, short>> todo[MX+5];

int main(){
  cin.tie(0)->sync_with_stdio(0);

  cin >> n >> m;
  for(int i=0; i<m; i++){
    cin >> x[i] >> P[i];
    v[x[i]].push_back(i);
  }
  for(int i=0; i<n; i++){
    for(int j=0; j<B; j++) dist[i][j]=1e9;
  }
  dist[x[0]][0]=0;

  set<pair<int, pii>> s;

  auto go=[&](int i, int d, int b){
    for(int c:{i+b, i-b}){
      if(c<0 || c>=n) continue;
      if(d+1<dist[c][b]){
        dist[c][b]=d+1;
        todo[d+1].pb({c, b});
      }
      if(d+1<dist[c][0]){
        dist[c][0]=d+1;
        todo[d+1].pb({c, 0});
      }
    }
  };

  todo[0].pb({x[0], 0});
  int d=0;
  while(true){
    pii p;
    while(true){
      while(d<MX && !sz(todo[d])) d++;
      if(d==MX) break;
      p=todo[d].back();
      todo[d].pop_back();
      if(!done[p.f][p.s]) break;
    }
    if(d==MX) break;
    int a=p.f, b=p.s;
    done[a][b]=1;
    // cout << a << " " << b << nl;
    if(a==x[1]){
      cout << d; return 0;
    }
    if(!b){
      for(int i:v[a]){
        if(P[i]>=B){
          for(int j=a%P[i]; j<n; j+=P[i]){
            if(d+abs(j-a)/P[i]<dist[j][0]){
              dist[j][0]=d+abs(j-a)/P[i];
              todo[dist[j][0]].pb({j, 0});
            }
          }
        }
        else{
          go(a, d, P[i]);
        }
      }
    }
    else{
      go(a, d, b);
    }
  }
  cout << -1;
}

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