Source code for submission s453

fn.cpp

  1. #include<cstdio>
  2. #include<cstdlib>
  3. #include<cstring>
  4.  
  5. #include<cmath>
  6. #include<cctype>
  7. #include<climits>
  8. #include<algorithm>
  9. #include<utility>
  10. #include<string>
  11.  
  12. #include<deque>
  13. #include<list>
  14. #include<map>
  15. #include<queue>
  16. #include<set>
  17. #include<stack>
  18. #include<vector>
  19.  
  20.  
  21. using namespace std;
  22.  
  23. #define REP(i,N) for (int i = 0; i < (N); i++)
  24. #define FOR(i,a,b) for (int i = (a); i <= (b); i++)
  25. #define FORI(i,a,b) for (int i = (a); i < (b); i++)
  26. #define FORD(i,a,b) for (int i = (a)-1; i >= (b); i--)
  27. #define DP(arg...) fprintf(stderr, ## arg)
  28.  
  29. typedef long long ll;
  30. typedef long double ld;
  31. typedef pair<int,int> ii;
  32.  
  33. int N,M;
  34. //vector<int> E[11000];
  35. int deg[11000];
  36.  
  37. void solve() {
  38. 	REP(i,N) deg[i] = 0;
  39. 	REP(i,M) { int a,b;
  40. 			scanf("%d%d", &a, &b); deg[a-1]++; deg[b-1]++;
  41.  
  42. 	}
  43. 	REP(i,N) { if (deg[i] >= 4) { printf("YES\n"); return; } }
  44. 	printf("NO\n");
  45.  
  46. }
  47.  
  48. int main() {
  49. 	while (scanf("%d%d", &N, &M) != EOF) {
  50. 		solve();
  51. 	}
  52. 	return 0;
  53. }
  54.