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1107 Social Clusters （30 分）
When register on a social network, you are always asked to specify your hobbies in order to find some potential friends with the same hobbies. A social cluster is a set of people who have some of their hobbies in common. You are supposed to find all the clusters.
Each input file contains one test case. For each test case, the first line contains a positive integer N (≤1000), the total number of people in a social network. Hence the people are numbered from 1 to N. Then N lines follow, each gives the hobby list of a person in the format:
Ki: hi[1] hi[2] ... hi[Ki]
where Ki (>0) is the number of hobbies, and hi[j] is the index of the j-th hobby, which is an integer in [1, 1000].
For each case, print in one line the total number of clusters in the network. Then in the second line, print the numbers of people in the clusters in non-increasing order. The numbers must be separated by exactly one space, and there must be no extra space at the end of the line.
83: 2 7 101: 42: 5 31: 41: 31: 44: 6 8 1 51: 4
34 3 1
一，关注点
1，关于拥有相同爱好的两个人，如何连接？当时使用的是hobby的vector里添加人的方式，然后两两结合。这是比较直白的方式。
2，标准方法不是开vector来存储人，而是直接用数组来存储第一个有此爱好的人，以后的人都与这个人连接。这种方法简单。
二，我的代码
#include#include #include using namespace std;const int max_n = 1100;int N = 0;int father[max_n];bool flag[max_n];int num_of_child[max_n];vector vec[max_n];void init() { for (int i = 1; i <= N; i++) { father[i] = i; }}bool cmp(int a, int b) { return a > b;}int findFather(int x) { int a = x; while (x != father[x]) { x = father[x]; } while (a != father[a]) { int z = a; a = father[a]; father[z] = x; } return x;}void Union(int x, int y) { int faA = findFather(x); int faB = findFather(y); if (faA != faB) { father[faA] = faB; }}int main() { int num = 0, id = 0, num_of_circle = 0, max_id = -1; scanf("%d", &N); init(); for (int i = 1; i <= N; i++) { scanf("%d:", &num); for (int j = 0; j < num; j++) { scanf("%d", &id); vec[id].push_back(i); if (id > max_id) { max_id = id; } } } for (int i = 0; i <= max_id; i++) { int temp = vec[i].size(); for (int j = 0; j < temp - 1; j++) { Union(vec[i][j], vec[i][j + 1]); } } for (int i = 1; i <= N; i++) { flag[findFather(i)] = true; num_of_child[findFather(i)]++; } for (int i =1; i <= N; i++) { if (flag[i] == true) { num_of_circle++; } } sort(num_of_child + 1, num_of_child + N + 1, cmp); printf("%d\n", num_of_circle); for (int i = 1; i <= num_of_circle; i++) { printf("%d", num_of_child[i]); if (i != num_of_circle) { printf(" "); } } return 0;}
三，标准代码
#include#include using namespace std;const int max_n = 1010;int father[max_n] = { 0 };int group_num[max_n] = { 0 };bool flag[max_n] = { false };int course[max_n] = { 0 };int findFather(int x) { int a = x; while (x != father[x]) { x = father[x]; } while (a != father[a]) { int z = a; a = father[a]; father[z] = x; } return x;}void Union(int a, int b) { int faA = findFather(a); int faB = findFather(b); if (faA != faB) { father[faA] = faB; }}bool cmp(int a, int b) { return a > b;}int main() { int N = 0; scanf("%d", &N); for (int i = 1; i <= N; i++) { father[i] = i; } for (int i = 1; i <= N; i++) { int num = 0; scanf("%d:", &num); for (int j = 0; j < num; j++) { int hobby = 0; scanf("%d", &hobby); if (course[hobby] == 0) { course[hobby] = i; } Union(i, course[hobby]); } } for (int i = 1; i <= N; i++) { if (father[i] != 0) { flag[findFather(i)] = true; ++group_num[findFather(i)]; } } sort(group_num + 1, group_num + N + 1, cmp); int count = 0; for (int i = 1; i <= N; i++) { if (flag[i] == true)count++; } printf("%d\n", count); int num = 0; for (int i = 1; i <= N; i++) { if (group_num[i] != 0) { printf("%d", group_num[i]); num++; if (num != count) { printf(" "); } } } return 0;}
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