Submission #786154

#	Time	Username	Problem	Language	Result	Execution time	Memory
786154		makanhulia	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	10 / 100	1 ms	1024 KiB

skyscraper

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

#define int long long

vector<int> baris[30005];
int n, m, tujuan, ans = LLONG_MAX;

void solve(int pos, int p, int count) {
  // cout << pos << " " << p << " " << count << endl;
  // return 0;
  if (pos == tujuan) {
    ans = min(count, ans);
    return;
  }
  // while (pos >= 0 and pos < n) {
  // if (pos < 0 or pos >= n) return;

  // if (pos-p >= 0) solve(pos-p, p, count+1);
  // if (pos+p < n) solve(pos+p, p, count+1);

  int cur = pos;
  int temp = 0;
  while (cur-p >= 0) {
    cur -= p;
    temp += 1;
    // cout << "cur " << cur << endl;
    if (!baris[cur].empty()) {
      // cout << "NOT EMPTY" << endl;
      for (int i = 0; i < baris[cur].size(); i++) {
        int save = baris[cur][i];
        baris[cur].erase(baris[cur].begin()+i);
        solve(cur, save, count+temp);
        baris[cur].push_back(save);
      }
    }
  }

  cur = pos;
  temp = 0;
  while (cur+p < n) {
    cur += p;
    temp += 1;
    // cout << "cur " << cur << endl;
    if (!baris[cur].empty()) {
      // cout << "NOT EMPTY" << endl;
      for (int i = 0; i < baris[cur].size(); i++) {
        int save = baris[cur][i];
        baris[cur].erase(baris[cur].begin()+i);
        solve(cur, save, count+temp);
        baris[cur].push_back(save);
      }
    }
  }
  
  // }
}

signed main() {
  int b, p, posstart, pstart;
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    cin >> b >> p;
    if (i == 0) {
      posstart = b;
      pstart = p;
    } else {
      if (i == 1) tujuan = b;
      // cout << b << endl;
      baris[b].push_back(p);
    }
  }

  solve(posstart, pstart, 0);
  if (ans == LLONG_MAX) cout << -1 << endl;
  else cout << ans << endl;
  // vector<int> a;
  // a.push_back(1);
  // a.push_back(2);

  // for (auto i: a) cout << i << " ";
  // cout << endl;
  
  // a.erase(a.begin()+1);
  // for (auto i: a) cout << i << " ";
  // cout << endl;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void solve(long long int, long long int, long long int)':
skyscraper.cpp:30:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |       for (int i = 0; i < baris[cur].size(); i++) {
      |                       ~~^~~~~~~~~~~~~~~~~~~
skyscraper.cpp:47:25: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |       for (int i = 0; i < baris[cur].size(); i++) {
      |                       ~~^~~~~~~~~~~~~~~~~~~
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:74:8: warning: 'pstart' may be used uninitialized in this function [-Wmaybe-uninitialized]
   74 |   solve(posstart, pstart, 0);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:74:8: warning: 'posstart' may be used uninitialized in this function [-Wmaybe-uninitialized]

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