hihoCoder#1066 无间道之并查集

 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 }