PAT 1063. Set Similarity (25)

http://pat.zju.edu.cn/contests/pat-a-practise/1063

Given two sets of integers, the similarity of the sets is defined to be N_c/N_t*100%, 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 (<=50) which is the total number of sets. Then N lines follow, each gives a set with a positive M (<=10⁴) and followed by M integers in the range [0, 10⁹]. After the input of sets, a positive integer K (<=2000) 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:

33 99 87 1014 87 101 5 877 99 101 18 5 135 18 9921 21 3

Sample Output:

50.0%33.3%

#include <cstdio>#include <set>using namespace std;set<int> s[50];int main(){//freopen("G:\\input.in", "r", stdin);int n;scanf("%d", &n);for (int i = 0; i < n; ++i){int num, x;for (scanf("%d", &num); num; --num){scanf("%d", &x);s[i].insert(x);}}int k;for (scanf("%d", &k); k; --k){int a, b;scanf("%d%d", &a, &b);int counta = s[a - 1].size(), countb = s[b - 1].size();int cnt = 0;for (set<int>::iterator iter = s[a - 1].begin(); iter != s[a - 1].end(); ++iter){if (s[b - 1].find(*iter) != s[b - 1].end())cnt++;}printf("%.1lf%%\n", cnt*1.0/(counta+countb-cnt)*100);}return 0;}

使用stl set_intersection set_union:

#include <cstdio>#include <iostream>#include <iomanip>#include <algorithm>#include <iterator>#include <set>using namespace std;set<int> s[50];int main(){//freopen("G:\\input.in", "r", stdin);int n;scanf("%d", &n);for (int i = 0; i < n; ++i){int num, x;for (scanf("%d", &num); num; --num){scanf("%d", &x);s[i].insert(x);}}int k;for (scanf("%d", &k); k; --k){int a, b;scanf("%d%d", &a, &b);set<int> inter, uni;set_intersection(s[a-1].begin(), s[a-1].end(), s[b-1].begin(), s[b-1].end(), inserter(inter, inter.begin()));//set_union(s[a-1].begin(), s[a-1].end(), s[b-1].begin(), s[b-1].end(), inserter(uni, uni.begin()));cout << setiosflags(ios::fixed) << setprecision(1) << inter.size() *100.0 / (s[a-1].size() + s[b-1].size() - inter.size()) << "%" << endl;}return 0;}