hihoCoder#1066 无间道之并查集

原题地址

 

并查集+路径压缩

数据量不大，没有加秩优化

 

代码：

 1 #include <iostream>

 2 #include <map>

 3 #include <cstring>

 4 

 5 using namespace std;

 6 

 7 #define SIZE 100010

 8 

 9 int disjoin[SIZE];

10 map<string, int> a2i;

11 

12 int find(int a) {

13   if (!disjoin[a] || disjoin[a] == a)

14     disjoin[a] = a;

15   else

16     disjoin[a] = find(disjoin[a]);

17   return disjoin[a];

18 }

19 

20 void merge(int a, int b) {

21   disjoin[find(a)] = find(b);

22 }

23 

24 bool check(int a, int b) {

25   return find(a) == find(b);

26 }

27 

28 int main() {

29   int N;

30   int op;

31   string a, b;

32   int ai, bi;

33   int num = 0;

34 

35   memset(disjoin, 0, sizeof(int) * SIZE);

36   cin >> N;

37   while (N--) {

38     cin >> op >> a >> b;

39     ai = a2i[a];

40     bi = a2i[b];

41     if (!a2i[a])

42       ai = a2i[a] = ++num;

43     if (!a2i[b])

44       bi = a2i[b] = ++num;

45 

46     if (op == 0)

47       merge(ai, bi);

48     else

49       cout << (check(ai, bi) ? "yes" : "no") << endl;

50   }

51   return 0;

52 }