Coloring

#include <bits/stdc++.h>
using namespace std;

long long p = 1000000007;

long long power(long long x, long long n) {
  if(n == 0) return (1 % p);
  long long xx = power(x, n/2);
  xx = (xx * xx) % p;
  if(n%2==1) xx = (xx * x) % p;
  return xx;
}

struct Vertex {
  set<int> adj;
  int color;
  bool badcolor[6];
};

int main() {
  int n, m;
  cin >> n >> m;
  Vertex E[n];
  for (int i = 0; i < m; ++i) {
    int u, v;
    cin >> u >> v;
    E[u - 1].adj.insert(v - 1);
    E[v - 1].adj.insert(u - 1);
  }
  priority_queue<pair<int, int>> heap;
  for (int i = 0; i < n; ++i) {
    E[i].color = -1;
    heap.push({-E[i].adj.size(), i});
    for (int j = 0; j < 6; ++j)
      E[i].badcolor[j] = false;
  }
  while (heap.size() > 0) {
    int v = heap.top().second;
    heap.pop();
    if (E[v].color != -1) continue;
    
    for (int i = 0; i < 6; ++i) {
      if (!E[v].badcolor[i]) {
        E[v].color = i;
        for (int u : E[v].adj) {
          E[u].badcolor[i] = true;
          E[u].adj.erase(v);
          heap.push({-E[u].adj.size(), u});
        }
        break;
      }
    }
  }
  for (int i = 0; i < n; ++i) {
    cout << E[i].color + 1 << ' ';
  }
  cout << endl;
  
  return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED