Submission #1128028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128028		VinhLuu	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	652 ms	25024 KiB

skyscraper

#include <bits/stdc++.h>
#define ll long long
#define all(lpv) lpv.begin(), lpv.end()
#define pot(x, y) lower_bound(x.begin(), x.end(), y) - x.begin() + 1
using namespace std;

#define lpv

#ifndef lpv
#include "AC.h"
#endif // lpv

//#define int long long

typedef tuple<int,int,int> tp;

const int N = 3e4 + 2;
const int block = 173;
const int oo = 2e9;

int n, m, b[N], p[N];
int f[block + 2][N];
vector<int> col[N];

#ifdef lpv
signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  #define task "v"
  if(fopen(task ".inp","r")) {
    freopen(task ".inp","r",stdin);
    freopen(task ".out","w",stdout);
  }

  cin >> n >> m;
  for(int i = 1; i <= m; i ++) {
    cin >> b[i] >> p[i];
    b[i]++;
    col[b[i]].push_back(i);
  }

  priority_queue<tp, vector<tp>, greater<tp>> pq;
  for(int i = 1; i <= n; i ++) {
    for(int k = 0; k <= block; k ++) f[k][i] = oo;
  }
  pq.push({f[0][b[1]] = 0, 0, b[1]});
  while(!pq.empty()) {
    int w, t, u; tie(w, t, u) = pq.top(); pq.pop();
    if(w > f[t][u]) continue;
    if(f[0][u] > f[t][u]) {
      pq.push({f[0][u] = f[t][u], 0, u});
    }
    if(t) {
      if(u - t >= 1 && f[t][u - t] > w + 1) {
        pq.push({f[t][u - t] = w + 1, t, u - t});
      }
      if(u + t <= n && f[t][u + t] > w + 1) {
        pq.push({f[t][u + t] = w + 1, t, u + t});
      }
      continue;
    }
    for(auto i : col[u]) {
      if(p[i] > block) {
        for(int j = u + p[i], cnt = 1; j <= n; j += p[i], cnt ++) if(f[0][j] > w + cnt) {
          pq.push({f[0][j] = w + cnt, 0, j});
        }
        for(int j = u - p[i], cnt = 1; j >= 1; j -= p[i], cnt ++) if(f[0][j] > w + cnt) {
          pq.push({f[0][j] = w + cnt, 0, j});
        }
      } else {
        if(u - p[i] >= 1 && f[p[i]][u - p[i]] > w + 1) {
          pq.push({f[p[i]][u - p[i]] = w + 1, p[i], u - p[i]});
        }
        if(u + p[i] <= n && f[p[i]][u + p[i]] > w + 1) {
          pq.push({f[p[i]][u + p[i]] = w + 1, p[i], u + p[i]});
        }
      }
    }
  }

  int ans = oo;

  for(int i = 0; i <= block; i ++) ans = min(ans, f[i][b[2]]);

  if(ans == oo) cout << -1 ;
  else cout << ans;
}

#endif // lpv

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:31:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |     freopen(task ".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:32:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |     freopen(task ".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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