Submission #245531

#	Time	Username	Problem	Language	Result	Execution time	Memory
245531		kevlee	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	822 ms	147440 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mod 1000000007
#define h1 7897897897897897
#define h2 7897466719774591
#define b1 98762051
#define b2 98765431
#define inf 1000000000
#define pi 3.1415926535897932384626
#define LMAX 9223372036854775807
#define ll long long
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vi vector<int>
#define vl vector<ll>
#define vp vector<pii>
#define SET(a, b) memset(a, b, sizeof(a));
#define all(x) (x).begin(), (x).end()
#define flush fflush(stdout)
#define debug printf("Hello\n")
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (a); i >= (b); i--)
int n, m, k, x, y, sum, cnt, ans = inf, b[30005], po[30005];
int d[30005][175];
vi v[30005];
const int SQ = 173;
struct state {
  int dist, pos, power; //for buildings: power = 0
  bool operator <(const state& rhs) const {
    return dist > rhs.dist;
  }
};
vector <pii> edges[30005][175]; //(position, power)
int main () {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  scanf("%d %d", &n, &m);
  FOR(i, 1, m) {
    scanf("%d %d", &b[i], &po[i]);
    v[b[i]].pb(po[i]);
  }
  FOR(i, 0, n-1) {
    sort(all(v[i]));
    auto it = unique(v[i].begin(), v[i].end());
    v[i].resize(distance(v[i].begin(), it));
    FOR(j, 0, 174) {
      d[i][j] = inf;
    }
  }
  d[b[1]][0] = 0;
  priority_queue <state> pq;
  pq.push((state){0, b[1], 0});
  while (!pq.empty()) {
    state cur = pq.top();
    pq.pop();
    if (d[cur.pos][cur.power] != cur.dist) continue;
    if (cur.pos == b[2]) {
      ans = min(ans, cur.dist);
      continue;
    }
    if (cur.power == 0) {
      for (auto p: v[cur.pos]) {
        if (p >= SQ) {
          for (int j = cur.pos - p, cost = 1; j >= 0; j -= p, cost++) {
            if (cur.dist + cost < d[j][0]) {
              d[j][0] = cur.dist + cost;
              pq.push((state){d[j][0], j, 0});
            }
          }
          for (int j = cur.pos + p, cost = 1; j < n; j += p, cost++) {
            if (cur.dist + cost < d[j][0]) {
              d[j][0] = cur.dist + cost;
              pq.push((state){d[j][0], j, 0});
            }
          }
        } else {
          if (cur.dist < d[cur.pos][p]) {
            d[cur.pos][p] = cur.dist;
            pq.push((state){d[cur.pos][p], cur.pos, p}); 
          }
        }
      }
    } else {
      if (cur.dist < d[cur.pos][0]) {
        d[cur.pos][0] = cur.dist;
        pq.push((state){d[cur.pos][0], cur.pos, 0});
      }
      if (cur.pos + cur.power < n && cur.dist + 1 < d[cur.pos + cur.power][cur.power]) {
        d[cur.pos + cur.power][cur.power] = cur.dist + 1;
        pq.push((state){d[cur.pos + cur.power][cur.power], cur.pos + cur.power, cur.power});
      }
      if (cur.pos - cur.power >= 0 && cur.dist + 1 < d[cur.pos - cur.power][cur.power]) {
        d[cur.pos - cur.power][cur.power] = cur.dist + 1;
        pq.push((state){d[cur.pos - cur.power][cur.power], cur.pos - cur.power, cur.power});
      }
    }
  }
  if (ans == inf) printf("-1\n");
  else printf("%d\n", ans);
  return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:41:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &m);
   ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &b[i], &po[i]);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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