1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <queue>
#include <set>
using namespace std;

bool visited[200000 + 2];
set<int> G[200000 + 2];

int dfs(int v, bool print_vertices) {
  if (visited[v] || G[v].empty()) {
    return 0;
  }

  visited[v] = true;

  if (print_vertices) {
    printf("%d ", v);
  }

  int size = 1;
  for (set<int>::iterator it = G[v].begin(); it != G[v].end(); it++) {
    size += dfs(*it, print_vertices);
  }

  return size;
}

int main() {
  int n, m, d;
  scanf("%d%d%d", &n, &m, &d);

  for (int i = 0; i < m; i++) {
    int a, b;
    scanf("%d%d", &a, &b);
    G[a].insert(b);
    G[b].insert(a);
  }

  //
  // First phase: recursively reduce all vertices with less then d edges.
  //
  memset(visited, false, sizeof(visited));

  queue<int> Q;
  for (int i = 1; i <= n; i++) {
    if (G[i].size() < d) {
      Q.push(i);
      visited[i] = true;
    }
  }

  while (!Q.empty()) {
    int v = Q.front();
    Q.pop();

    for (set<int>::iterator it = G[v].begin(); it != G[v].end(); it++) {
      int w = *it;
      G[w].erase(v);
      if (G[w].size() < d && !visited[w]) {
        Q.push(w);
        visited[w] = true;
      }
    }

    G[v].clear();
  }

  //
  // Second phase: find the size of the largest subgraph and print it out.
  //
  memset(visited, false, sizeof(visited));

  int max_v = 0;
  int max_size = 0;
  for (int i = 1; i <= n; i++) {
    int graph_size = dfs(i, false);
    if (max_size < graph_size) {
      max_v = i;
      max_size = graph_size;
    }
  }

  if (max_size == 0) {
    printf("NIE\n");
  } else {
    printf("%d\n", max_size);

    memset(visited, false, sizeof(visited));
    dfs(max_v, true);
  }

  return 0;
}