hdu 1077计算几何

/*
* hdu1077/win.cpp
* Created on: 2012-10-25
* Author    : ben
*/
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
#include <stack>
#include <string>
#include <vector>
#include <deque>
#include <list>
#include <functional>
#include <numeric>
#include <cctype>
using namespace std;
const int MAXN = 310;
const double eps = 1e-4;
typedef struct MyPoint {
double x, y;
MyPoint() {        x = y = 0;    }
MyPoint(double xx, double yy) {        x = xx;        y = yy;    }
MyPoint(const MyPoint &p1, const MyPoint &p2) {
x = (p1.x + p2.x) / 2;
y = (p1.y + p2.y) / 2;
}
}MyPoint;
inline double mydistance(const MyPoint &p1, const MyPoint &p2) {
return sqrt((p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y));
}
inline MyPoint operator-(const MyPoint &p1, const MyPoint &p2) {
return MyPoint(p1.x - p2.x, p1.y - p2.y);
}
MyPoint points[MAXN];
int N, ans;

inline void getcenter(const MyPoint &p1, const MyPoint &p2, MyPoint &c) {
MyPoint diff = p1 - p2;
MyPoint mid(p1, p2);
double angle;
double high = mydistance(p1, p2) / 2;
high = sqrt(1 - high * high);
if (fabs(diff.x) < eps) {
c.x = mid.x + high;
c.y = mid.y;
} else {
angle = atan(diff.y / diff.x);
c.x = mid.x - high * sin(angle);
c.y = mid.y + high * cos(angle);
}
}

inline bool myjudge(const MyPoint &p1, const MyPoint &p2) {
double dis = mydistance(p1, p2);
return dis <= 1 + eps;
}

int main() {
#ifndef ONLINE_JUDGE
freopen("data.in" , "r", stdin);
#endif
int T;
scanf("%d", &T);
while(T--) {
scanf("%d", &N);
for(int i = 0; i < N; i++) {
scanf("%lf%lf", &points[i].x, &points[i].y);
}
ans = 1;
MyPoint p;
for(int i = 0; i < N; i++) {
for(int j = i + 1; j < N; j++) {
if(mydistance(points[i], points[j]) > 2 + eps + eps) {
continue;
}
getcenter(points[i], points[j], p);
int t = 0;
for(int k = 0; k < N; k++) {
if(myjudge(p, points[k])) {
t++;
}
}
if(t > ans) {
ans = t;
}
}
}
printf("%d\n", ans);
}
return 0;
}