Submission #552735

#	Time	Username	Problem	Language	Result	Execution time	Memory
552735		iancu	Towns (IOI15_towns)	C++14	25 / 100	20 ms	1096 KiB

towns

    #include "towns.h"
    #include <vector>
     
    using namespace std;
     
    int hubDistance(int N, int sub) {
      vector<vector<int>> dist(N, vector<int>(N, -1));
      auto getDist = [&dist](int a, int b) {
        if (dist[a][b] == -1)
          dist[a][b] = dist[b][a] = getDistance(a, b);
        return dist[a][b];
      };
      int D1, D2, dist_max = 0;
      for (int i = 1; i < N; ++i)
        if (getDist(0, i) > dist_max) {
          dist_max = getDist(0, i);
          D1 = i;
        }
      dist_max = 0;
      for (int i = 0; i < N; ++i)
        if (i != D1 && getDist(D1, i) > dist_max) {
          dist_max = getDist(D1, i);
          D2 = i;
        }
      int R = getDist(D1, D2);
      for (int i = 0; i < N; ++i)
        if (i != D1 && i != D2) {
          int dist_i = (getDist(D1, i) - getDist(D2, i) + getDist(D1, D2)) / 2;
          R = min(R, max(dist_i, getDist(D1, D2) - dist_i));
        }
      return R;
    }

Compilation message (stderr)

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:6:32: warning: unused parameter 'sub' [-Wunused-parameter]
    6 |     int hubDistance(int N, int sub) {
      |                            ~~~~^~~
towns.cpp:9:19: warning: 'D1' may be used uninitialized in this function [-Wmaybe-uninitialized]
    9 |         if (dist[a][b] == -1)
      |                   ^
towns.cpp:10:48: warning: 'D2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   10 |           dist[a][b] = dist[b][a] = getDistance(a, b);
      |                                     ~~~~~~~~~~~^~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 12 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 39