1063 Set Similarity

Given two sets of integers, the similarity of the sets is defined to be /, where N​c​​ is the number of distinct common numbers shared by the two sets, and N​t​​ is the total number of distinct numbers in the two sets. Your job is to calculate the similarity of any given pair of sets.

Input Specification:

Each input file contains one test case. Each case first gives a positive integer N (≤) which is the total number of sets. Then N lines follow, each gives a set with a positive M (≤) and followed by M integers in the range [0]. After the input of sets, a positive integer K (≤) is given, followed by K lines of queries. Each query gives a pair of set numbers (the sets are numbered from 1 to N). All the numbers in a line are separated by a space.

Output Specification:

For each query, print in one line the similarity of the sets, in the percentage form accurate up to 1 decimal place.

Sample Input:

3
3 99 87 101
4 87 101 5 87
7 99 101 18 5 135 18 99
2
1 2
1 3

 

Sample Output:

50.0%
33.3%

题意：

　　计算两个set集合的相似度。

思路：

　　模拟。

Code：

#include <bits/stdc++.h>

using namespace std;

int main() {
    int n, k, t;
    cin >> n;
    vector<set<int> > v(n + 1);
    for (int i = 1; i <= n; ++i) {
        cin >> k;
        for (int j = 0; j < k; ++j) {
            cin >> t;
            v[i].insert(t);
        }
    }
    cin >> k;
    for (int i = 0; i < k; ++i) {
        int q1, q2;
        cin >> q1 >> q2;
        int total = v[q1].size() + v[q2].size();
        int count = 0;
        for (int s : v[q1])
            if (v[q2].find(s) != v[q2].end()) count++;
        cout << fixed << setprecision(1)
             << (double)count / (total - count) * 100 << "%" << endl;
    }

    return 0;
}