//A
#define _CRT_SECURE_NO_WARNINGS
#include <cstdio>
#include <cmath>
#include <algorithm>
#include<algorithm>
using namespace std;
const double MAX_DIST = 1e100;
const int MAXN = 200010;
struct Point {
double x, y;
bool flag;
};
inline double dist(const Point &a, const Point &b) {
if (a.flag != b.flag)
return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
else
return MAX_DIST;
}
Point pt[MAXN];
int y_sort[MAXN];
inline bool x_cmp(const Point &a, const Point &b) {
return a.x < b.x;
}
inline bool y_cmp(const int &a, const int &b) {
return pt[a].y < pt[b].y;
}
double shortest_distance(int left, int right) {
if (right - left == 1)
return dist(pt[left], pt[right]);
else if (right - left == 2)
return min(min(dist(pt[left], pt[left + 1]), dist(pt[left], pt[left + 2])),
dist(pt[left + 1], pt[left + 2]));
int mid = (left + right) >> 1;
double mind = min(shortest_distance(left, mid), shortest_distance(mid + 1, right));
if (mind == 0) return 0;
int yn = 0;
for (int i = mid; pt[mid].x - pt[i].x < mind && i >= left; --i)
y_sort[yn++] = i;
int y_mid = yn;
for (int i = mid + 1; pt[i].x - pt[mid].x < mind && i <= right; ++i)
y_sort[yn++] = i;
for (int i = 0; i < y_mid; ++i)
for (int j = y_mid; j < yn; ++j)
mind = min(mind, dist(pt[y_sort[i]], pt[y_sort[j]]));
return mind;
}
int main() {
int T;
scanf("%d", &T);
while (T--) {
int n;
scanf("%d", &n);
for (int i = 0; i < n; ++i) {
scanf("%lf%lf", &pt[i].x, &pt[i].y);
pt[i].flag = false;
}
for (int i = n; i < 2 * n; ++i) {
scanf("%lf%lf", &pt[i].x, &pt[i].y);
pt[i].flag = true;
}
sort(pt, pt + 2 * n, x_cmp);
printf("%.3f\n", shortest_distance(0, 2 * n - 1));
}
}
poj 3714 分治加剪枝
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