56 lines
1.3 KiB
C++
56 lines
1.3 KiB
C++
#include <iostream>
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#include <cstring>
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#include <string>
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#include <algorithm>
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#include <cmath>
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#include <vector>
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#include <set>
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#include <queue>
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#include <map>
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using namespace std;
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#define INF 1e9
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#define maxn 1010
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#define rep(i,x,y) for(int i=x;i<=y;i++)
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#define mset(x) memset(x,0,sizeof(x))
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typedef pair<int, int> pii;
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int t, n;
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struct point{
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int x, y;
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}p[maxn];
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map< pii, int > tb;
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map< pii, int >::iterator it;
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bool cmp(const point& a, const point& b){
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return (a.x==b.x&&a.y<b.y) || a.x<b.x;
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}
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int gcd(int a, int b){
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if(b==0) return a;
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return gcd(b, a%b);
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}
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int main(){
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cin>>t;
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while(t--){
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cin>>n;
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rep(i,1,n) scanf("%d%d", &p[i].x, &p[i].y);
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sort(p+1, p+n+1, cmp);
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int cnt=0;
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rep(i,1,n-2){
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tb.clear();
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rep(j,i+1,n){
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int dx = p[j].x - p[i].x;
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int dy = p[j].y - p[i].y;
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int d = gcd(dx, dy);
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dx = dx/d;
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dy = dy/d;
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tb[make_pair(dx,dy)]++;
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}
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for(it=tb.begin(); it!=tb.end(); it++){
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int x = it->second;
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if(x>=2)
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cnt += x*(x-1)/2; //C(x,2)
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}
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}
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cout<<cnt<<endl;
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}
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return 0;
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}
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