[hdu1272]并查集

思路：裸并查集模板啊。。

 1 #include <iostream>

 2 #include <cstdio>

 3 #include <algorithm>

 4 #include <cstdlib>

 5 #include <cstring>

 6 #include <map>

 7 #include <queue>

 8 #include <deque>

 9 #include <cmath>

10 #include <vector>

11 #include <ctime>

12 #include <cctype>

13 #include <set>

14 

15 using namespace std;

16 

17 #define mem0(a) memset(a, 0, sizeof(a))

18 #define lson l, m, rt << 1

19 #define rson m + 1, r, rt << 1 | 1

20 #define define_m int m = (l + r) >> 1

21 #define Rep(a, b) for(int a = 0; a < b; a++)

22 #define lowbit(x) ((x) & (-(x)))

23 #define constructInt4(name, a, b, c, d) name(int a = 0, int b = 0, int c = 0, int d = 0): a(a), b(b), c(c), d(d) {}

24 #define constructInt3(name, a, b, c) name(int a = 0, int b = 0, int c = 0): a(a), b(b), c(c) {}

25 #define constructInt2(name, a, b) name(int a = 0, int b = 0): a(a), b(b) {}

26 

27 typedef double db;

28 typedef long long LL;

29 typedef pair<int, int> pii;

30 typedef multiset<int> msi;

31 typedef multiset<int>::iterator msii;

32 typedef set<int> si;

33 typedef set<int>::iterator sii;

34 typedef vector<int> vi;

35 

36 const int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};

37 const int dy[8] = {0, -1, 0, 1, -1, 1, 1, -1};

38 const int maxn = 1e5 + 7;

39 const int maxm = 1e5 + 7;

40 const int maxv = 1e7 + 7;

41 const int MD = 1e9 +7;

42 const int INF = 1e9 + 7;

43 const double PI = acos(-1.0);

44 const double eps = 1e-10;

45 

46 struct UnionFindSets {

47     vi f;

48     int N;

49     UnionFindSets() { f.clear(); }

50     void clear() { f.clear(); }

51     void resize(int n) { N = n + 2; f.resize(n + 5); }

52     void Init() { for (int i = 1; i <= N; i++) f[i] = i; }

53     int get(int u) { if (u == f[u]) return u; return f[u] = get(f[u]); }

54     void add(int u, int v) { f[get(u)] = get(v); }

55     bool find(int u, int v) { return get(u) == get(v); }

56 };

57 

58 UnionFindSets ufs;

59 

60 bool mark[100007];

61 

62 int main() {

63     //freopen("in.txt", "r", stdin);

64     ufs.resize(1e5 + 7);

65     ufs.Init();

66     int v = 0, a, b, yes = 1;

67     while (1) {

68         scanf("%d%d", &a, &b);

69         if (!v) v = a;

70         mark[a] = mark[b] = 1;

71         if (a == -1 && b == -1) break;

72         if (a == 0 && b == 0) {

73             for (int i = 1; i <= 1e5; i++) {

74                 if (mark[i] && ufs.get(i) != ufs.get(v)) {

75                     yes = 0;

76                     break;

77                 }

78             }

79             if (yes) puts("Yes");

80             else puts("No");

81             ufs.Init();

82             mem0(mark);

83             v = 0;

84             yes = 1;

85             continue;

86         }

87         if (ufs.find(a, b)) {

88             yes = 0;

89         }

90         ufs.add(a, b);

91     }

92     return 0;

93 }

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