Submission #917096

#	Time	Username	Problem	Language	Result	Execution time	Memory
917096		rxlfd314	Rail (IOI14_rail)	C++17	30 / 100	292 ms	98952 KiB

rail

#include "rail.h"
#include <bits/stdc++.h>
using namespace std;
using ari2 = array<int, 2>;

#define vt vector
#define size(x) (int((x).size()))
#define all(x) begin(x), end(x)

#define REP(a, b, c, d) for (int a = (b); (d) > 0 ? a <= (c) : a >= (c); a += (d))
#define FOR(a, b, c) REP(a, b, c, 1)
#define ROF(a, b, c) REP(a, b, c, -1)

void findLocation(int N, int first, int location[], int stype[]) {
  memset(stype, 0, sizeof(stype));
  location[0] = first;
  stype[0] = 1;
  if (N < 2)
    return;
  vt<vt<int>> D(N, vt<int>(N));
  FOR(i, 0, N-1)
    FOR(j, i+1, N-1)
      D[i][j] = D[j][i] = getDistance(i, j);
  int f[N];
  FOR(i, 0, N-1) {
    ari2 best = {INT_MAX, 0};
    FOR(j, 0, N-1)
      if (j != i)
        best = min(best, ari2{D[i][j], j});
    f[i] = best[1];
  }
  vt<int> adj[N];
  FOR(i, 0, N-1) {
    adj[i].push_back(f[i]);
    if (i != f[f[i]])
      adj[f[i]].push_back(i);
  }
  function<void(int)> dfs = [&](int i) {
    for (int j : adj[i]) {
      if (stype[j])
        continue;
      location[j] = location[i] + (stype[i] == 1 ? 1 : -1) * D[i][j];
      stype[j] = 3 - stype[i];
      dfs(j);
    }
  };
  dfs(0);
  FOR(i, 0, N-1) {
    if (stype[i])
      continue;
    int j = f[i];
    if (D[0][i] == D[0][f[0]] + D[f[0]][i]) { // to the left of 0
      if (D[0][i] > D[0][j]) { // i is 2
        stype[j] = 1;
        location[j] = location[f[0]] - D[f[0]][j];
        dfs(j);
      } else {
        stype[i] = 1;
        location[i] = location[f[0]] - D[f[0]][i];
        dfs(i);
      }
    } else {
      if (D[0][i] > D[0][j]) { // i is 1
        stype[j] = 2;
        location[j] = location[0] + D[0][j];
        dfs(j);
      } else {
        stype[i] = 2;
        location[i] = location[0] + D[0][i];
        dfs(i);
      }
    }
  }
}

Compilation message (stderr)

rail.cpp: In function 'void findLocation(int, int, int*, int*)':
rail.cpp:15:27: warning: 'sizeof' on array function parameter 'stype' will return size of 'int*' [-Wsizeof-array-argument]
   15 |   memset(stype, 0, sizeof(stype));
      |                          ~^~~~~~
rail.cpp:14:57: note: declared here
   14 | void findLocation(int N, int first, int location[], int stype[]) {
      |                                                     ~~~~^~~~~~~
rail.cpp:15:20: warning: argument to 'sizeof' in 'void* memset(void*, int, size_t)' call is the same expression as the destination; did you mean to dereference it? [-Wsizeof-pointer-memaccess]
   15 |   memset(stype, 0, sizeof(stype));
      |                    ^~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 22 / 22
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44