蓝桥杯2021

 1 #include<iostream>
 2 #include<vector>
 3 #include<set>
 4 using namespace std;
 5 typedef pair<int,int> PII;
 6 typedef pair<PII,int> PIII;
 7 vector<PII> v;
 8 set<PIII> s;
 9 int x,y;
10 int gcd(int a,int b){
11     if(b==0) return a;
12     return gcd(b,a%b);
13 }
14 int main(){
15     cin>>x>>y;
16 
17     for(int i=0;i<x;i++){
18         for(int j=0;j<y;j++){
19             v.push_back({i,j});
20         }
21     }
22 
23     for(int i=0;i<v.size();i++){
24         for(int j=i+1;j<v.size();j++){
25             int x1=v[i].first;
26             int y1=v[i].second;
27             int x2=v[j].first;
28             int y2=v[j].second;
29             int A=y1-y2,B=x2-x1,C=x1*y2-x2*y1;
30             int gcdd=gcd(gcd(A,B),C);
31             s.insert({{B/gcdd,A/gcdd},C/gcdd});
32         }
33     }
34     
35     cout<<s.size();
36     return 0;
37     //答案40257
38 }