Submission #229614

#	Time	Username	Problem	Language	Result	Execution time	Memory
229614		Nightlight	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	36 / 100	1061 ms	45176 KiB

skyscraper

#include <queue>
#include <cstdio>
#include <tuple>
#include <cstring>
#define pii pair<int, int>
#define piii tuple<int, int, int>
#define mt make_tuple
#define push_back emplace_back
using namespace std;

int N, M;
pii A[30005];
int dist[30005][180];
int vis[30005][180];
vector<pii> adj[30005];
vector<int> dog[30005];

void BFS() {
  priority_queue<piii> pq;
  memset(dist, 0x3f3f3f3f, sizeof(dist));
  memset(vis, 0x3f3f3f3f, sizeof(vis));
  pq.push(make_tuple(0, A[0].first, 0));
  dist[A[0].first][0] = 0;
  int u, mov; int trav;
  while(!pq.empty()) {
    tie(trav, u, mov) = pq.top();
    pq.pop();
    if(dist[u][mov] < trav || vis[u][mov] <= trav) continue;
    if(mov != 0) {
      if(u - mov >= 0 && trav + 1 < dist[u - mov][mov]) {
        dist[u - mov][mov] = trav + 1;
        pq.push(make_tuple(trav + 1, u - mov, mov));
      }
      if(u + mov <= N && trav + 1 < dist[u + mov][mov]) {
        dist[u + mov][mov] = trav + 1;
        pq.push(make_tuple(trav + 1, u + mov, mov));
      }
      if(dist[u][0] > trav) {
        dist[u][0] = trav;
        pq.push(make_tuple(trav, u, 0));
      }
    }else {
      int v, w;
      for(pii now : adj[u]) {
        v = now.first, w = now.second + trav;
        if(w < dist[v][0]) {
          dist[v][0] = w;
          pq.push(make_tuple(w, v, 0));
        }
      }
      for(int v : dog[u]) {
        if(trav < dist[u][v]) {
          dist[u][v] = trav;
          pq.push(make_tuple(trav, u, v));
        }
      }
    }
    vis[u][mov] = trav;
  }
  if(dist[A[1].first][0] == 0x3f3f3f3f) puts("-1");
  else printf("%d\n", dist[A[1].first][0]);
}

int main() {
//  freopen("out.txt", "w", stdout);
  scanf("%d %d", &N, &M);
  int pos, mov;
  for(int i = 0; i < M; i++) {
    scanf("%d %d", &pos, &mov);
    A[i] = make_pair(pos, mov);
    if(mov * mov > N) {
      for(int i = pos - mov, j = 1; i >= 0; i -= mov, j++) {
        adj[pos].push_back(i, j);
      }
      for(int i = pos + mov, j = 1; i <= N; i += mov, j++) {
        adj[pos].push_back(i, j);
      }
    }else {
      dog[pos].push_back(mov);
    }
  }
  BFS();
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:66:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &N, &M);
   ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:69:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &pos, &mov);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~

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