2022-11-06：给定平面上 n 个点，x 和 y 坐标都是整数， 找出其中的一对点的距离，使得在这 n 个点的所有点对中，该距离为所有点对中最小的。 返回最短距离，精确到小数点后面 4 位。

use std::iter::repeat;
fn main() {    unsafe {        let input: [i32; 7] = [3, 1, 1, 1, 2, 2, 2];        let mut input_index = 0;        let n = input[input_index];        // N = n as usize;        input_index += 1;        points = repeat(Point::new(0.0, 0.0)).take(n as usize).collect();        merge = repeat(Point::new(0.0, 0.0)).take(n as usize).collect();        deals = repeat(Point::new(0.0, 0.0)).take(n as usize).collect();        for i in 0..n {            let x = input[input_index];            input_index += 1;            let y = input[input_index];            input_index += 1;            points[i as usize].x = x as f64;            points[i as usize].y = y as f64;        }        points.sort_by(|a, b| {            if a.x <= b.x {                core::cmp::Ordering::Less            } else {                core::cmp::Ordering::Greater            }        });        let ans = nearest(0, n - 1);        println!("{:.4}", ans);    }}
static mut points: Vec<Point> = vec![];static mut merge: Vec<Point> = vec![];static mut deals: Vec<Point> = vec![];
#[derive(Debug, Copy, Clone)]struct Point {    x: f64,    y: f64,}
impl Point {    fn new(a: f64, b: f64) -> Self {        Self { x: a, y: b }    }}
fn nearest(left: i32, right: i32) -> f64 {    unsafe {        let mut ans = f64::MAX;        if (left == right) {            return ans;        }        let mut mid = (right + left) / 2;        let mid_x = points[mid as usize].x;        ans = get_min(nearest(left, mid), nearest(mid + 1, right));        let mut p1 = left;        let mut p2 = mid + 1;        let mut merge_size = left;        let mut deal_size = 0;        while (p1 <= mid && p2 <= right) {            if points[p1 as usize].y <= points[p2 as usize].y {                merge[merge_size as usize] = points[p1 as usize];                p1 += 1;            } else {                merge[merge_size as usize] = points[p2 as usize];                p2 += 1;            }            if (f64::abs(merge[merge_size as usize].x - mid_x) <= ans) {                deals[deal_size as usize] = merge[merge_size as usize];                deal_size += 1;            }            merge_size += 1;        }        while (p1 <= mid) {            merge[merge_size as usize] = points[p1 as usize];            p1 += 1;            if (f64::abs(merge[merge_size as usize].x - mid_x) <= ans) {                deals[deal_size as usize] = merge[merge_size as usize];                deal_size += 1;            }            merge_size += 1;        }        while (p2 <= right) {            merge[merge_size as usize] = points[p2 as usize];            p2 += 1;            if (f64::abs(merge[merge_size as usize].x - mid_x) <= ans) {                deals[deal_size as usize] = merge[merge_size as usize];                deal_size += 1;            }            merge_size += 1;        }        for i in left..=right {            points[i as usize] = merge[i as usize];        }        for i in 0..deal_size {            for j in i + 1..deal_size {                if (deals[j as usize].y - deals[i as usize].y >= ans) {                    break;                }                ans = get_min(                    ans,                    distance(&mut deals[i as usize], &mut deals[j as usize]),                );            }        }        return ans;    }}
fn distance(a: &mut Point, b: &mut Point) -> f64 {    let x = a.x - b.x;    let y = a.y - b.y;    return f64::sqrt(x * x + y * y);}
fn get_max<T: Clone + Copy + std::cmp::PartialOrd>(a: T, b: T) -> T {    if a > b {        a    } else {        b    }}
fn get_min<T: Clone + Copy + std::cmp::PartialOrd>(a: T, b: T) -> T {    if a < b {        a    } else {        b    }}