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：

#include <iostream>
#include <map>
#include <cstring>

using namespace std;

#define SIZE 100010

int disjoin[SIZE];
map<string, int> a2i;

int find(int a) {
  if (!disjoin[a] || disjoin[a] == a)
    disjoin[a] = a;
  else
    disjoin[a] = find(disjoin[a]);
  return disjoin[a];
}

void merge(int a, int b) {
  disjoin[find(a)] = find(b);
}

bool check(int a, int b) {
  return find(a) == find(b);
}

int main() {
  int N;
  int op;
  string a, b;
  int ai, bi;
  int num = 0;

  memset(disjoin, 0, sizeof(int) * SIZE);
  cin >> N;
  while (N--) {
    cin >> op >> a >> b;
    ai = a2i[a];
    bi = a2i[b];
    if (!a2i[a])
      ai = a2i[a] = ++num;
    if (!a2i[b])
      bi = a2i[b] = ++num;

    if (op == 0)
      merge(ai, bi);
    else
      cout << (check(ai, bi) ? "yes" : "no") << endl;
  }
  return 0;
}