제출 #41889

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
41889		funcsr	도시들 (IOI15_towns)	C++14	0 / 100	1116 ms	524288 KiB

towns

#include "towns.h"
#include <vector>
#include <iostream>
#include <algorithm>
#include <queue>
#include <cassert>
#include <set>
using namespace std;
typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define pb push_back
#define _1 first
#define _2 second
#define INF 1145141919
#define MOD 1000000007
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())

#define MAX_V 300
int dist[MAX_V][MAX_V];
int U[MAX_V];
vector<int> R[MAX_V];
int find(int x) {
  if (U[x] == x) return x;
  return U[x] = find(U[x]);
}
void unite(int x, int y) {
  x = find(x), y = find(y);
  if (x == y) return;
  U[x] = y;
}
vector<P> G[MAX_V];
int dfs(int x, int p, int r) {
  int ret = r;
  for (P pp : G[x]) if (pp._1 != p) {
    int t = pp._1, len = pp._2;
    ret = max(ret, dfs(t, x, r+len));
  }
  return ret;
}

int hubDistance(int N, int sub) {
  rep(i, MAX_V) rep(j, MAX_V) dist[i][j] = 0;
  rep(i, N) rep(j, i) dist[i][j] = dist[j][i] = getDistance(i, j);
  set<int> nokori;
  rep(i, N) nokori.insert(i);
  int V = N;

  while (nokori.size() >= 2) {
    rep(i, V) U[i] = i;
    if (nokori.size() > 2) {
      for (int u : nokori) for (int v : nokori) if (u < v) {
        int l = dist[u][v];
        vector<int> vs;
        for (int x : nokori) if (x != u && x != v) vs.pb(dist[x][u]-dist[x][v]);
        sort(all(vs)); uniq(vs);
        if (vs.size() > 1) continue;
        unite(u, v);
      }
    }
    else {
      unite(*nokori.begin(), *nokori.rbegin());
    }
    rep(i, V) R[i].clear();
    for (int x : nokori) R[find(x)].pb(x);
    rep(i, V) if (R[i].size()) {
      assert(R[i].size() >= 2);
      int x0 = R[i][0], x1 = R[i][1];
      for (int x : R[i]) nokori.erase(x);
      if (nokori.empty()) assert(R[i].size() >= 3);
      int tekitou = -1;
      if (nokori.empty()) tekitou = R[i][2];
      else tekitou = *nokori.begin();
      int sum = dist[x0][x1], diff = dist[x0][tekitou] - dist[x1][tekitou];
      int a = (sum+diff)/2;
      int root = V++;
      G[root].pb(P(x0, a));
      G[x0].pb(P(root, a));
      dist[x0][root] = dist[root][x0] = a;
      for (int x : R[i]) if (x != x0) {
        int d = dist[x0][x] - a;
        dist[x][root] = dist[root][x] = d;
        G[root].pb(P(x, d));
        G[x].pb(P(root, d));
      }
      for (int x : nokori) dist[root][x] = dist[x][root] = dist[x0][x] - a;
      assert(V <= MAX_V);
      nokori.insert(root);
      break;
    }
  }
  int R = INF;
  rep(i, V) {
    R = min(R, dfs(i, -1, 0));
  }
  return R;
}

컴파일 시 표준 에러 (stderr) 메시지

towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:53:13: warning: unused variable 'l' [-Wunused-variable]
         int l = dist[u][v];
             ^
towns.cpp:92:7: warning: declaration of 'R' shadows a global declaration [-Wshadow]
   int R = INF;
       ^
towns.cpp:22:13: note: shadowed declaration is here
 vector<int> R[MAX_V];
             ^
towns.cpp: At global scope:
towns.cpp:42:28: warning: unused parameter 'sub' [-Wunused-parameter]
 int hubDistance(int N, int sub) {
                            ^

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