分析
平面最近点对板子题。虽然我是看了lyd大佬的标程才会的......所以代码和标程.......
代码
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define il inline
#define re register
#define tie0 cin.tie(0),cout.tie(0)
#define fastio ios::sync_with_stdio(false)
#define File(x) freopen(x".in","r",stdin);freopen(x".out","w",stdout)
using namespace std;
typedef long long ll;
typedef long double ld;
template <typename T> inline void read(T &x) {
T f = 1; x = 0; char c;
for (c = getchar(); !isdigit(c); c = getchar()) if (c == '-') f = -1;
for ( ; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
x *= f;
}
const double INF = 0x3f3f3f3f;
const double eps = 1e-7;
struct rd {
int x, y;
bool army;
bool operator < (const rd &k) const { return x < k.x; }
} ai[200005];
int n;
double dis(rd a, rd b) {
if (a.army == b.army) return INF;
return sqrt((ld)(a.x - b.x) * (a.x - b.x) + (ld)(a.y - b.y) * (a.y - b.y));
}
double raid(int l, int r) {
if (l == r) return INF;
if (r == l + 1) return dis(ai[l], ai[r]);
int mid = l + r >> 1;
double ans = min(raid(l, mid), raid(mid, r));
for (int i = mid - 1; i >= l; --i) {
if (ai[mid].x - ai[i].x + eps > ans) break;
for (int j = mid + 1; j <= r; ++j) {
if (ai[j].x - ai[i].x + eps > ans) break;
ans = min(ans, dis(ai[i], ai[j]));
}
}
return ans;
}
void solve() {
read(n);
for (int i = 1; i <= n; ++i) {
read(ai[i].x), read(ai[i].y);
ai[i].army = 0;
}
for (int i = 1; i <= n; ++i) {
read(ai[i+n].x), read(ai[i+n].y);
ai[i+n].army = 1;
}
sort(ai + 1, ai + 1 + n * 2);
printf("%.3f\n", raid(1, 2 * n));
}
int main() {
int t;
read(t);
while (t--) solve();
return 0;
}