Submission #1690906

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Source Code Expand

#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <climits>
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <string>
#include <sstream>
#include <vector>
#include <map>
#include <set>
#include <complex>
#include <functional>
#include <utility>
#include <iterator>

#define REP(i, n) for(int i = 0; i < (int)(n); ++i)
#define FOR(i, m, n) for(int i = (m); i < (int)(n); ++i)
#define ALL(x) (x).begin(), (x).end()
#define INF 2000000000

#ifdef LOCAL
  #define eprintf(...) fprintf(stdout, __VA_ARGS__)
#else
  #define eprintf(...) 0
#endif

using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef unsigned int uint;

const double PI = 3.1415926535897932384626433832795;

vector<vector<bool>> vv;
int n, m;
int maxnum = 1;

void recur(int count, vector<int> v) {
  /*
  eprintf("recur count:%d, v.size:%llu  ", count, v.size());
  REP(i, v.size()) {
    eprintf("%d, ", v[i]);
  }
  eprintf("\n");
  */
  if(count != n) {
    recur(count+1, v);
    v.push_back(count);
    recur(count+1, v);
  }
  else {
    eprintf("  check: ");
    REP(i, v.size()) {
      eprintf("%d, ", v[i]);
    }
    eprintf("\n");
    for(int i = 0; i < (int)v.size() - 1; ++i) {
      for(int j = i + 1; j < (int)v.size(); ++j) {
        if(vv[v[i]][v[j]] == false) {
          //eprintf("    i:%d j:%d false\n", i, j);
          return;
        }
      }
    }
    maxnum = max(maxnum, (int)v.size());
    return;
  }
}

int main() {
  cin >> n >> m;
  vv.resize(n);
  REP(i, n) {
    vv[i] = vector<bool>(n, false);
  }
  int x, y;
  REP(i, m) {
    cin >> x >> y;
    x--; y--;
    vv[x][y] = true;
    vv[y][x] = true;
  }
  if(m == 0) {
    cout << 1 << endl;
    return 0;
  }
  
  vector<int> v1;
  vector<int> v2;
  v2.push_back(0);
  recur(1, v1);
  recur(1, v2);
  cout << maxnum << endl;

  return 0;
}

Submission Info

Judge Result