RT 求调 谢谢

#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e15;
int n;
struct Point {
    long long x, y;
    Point(long long x = 0, long long y = 0): x(x), y(y) {}
} P[400005];

bool cmp1(Point A, Point B) {
    if (A.x != B.x) return A.x < B.x;
    return A.y < B.y;
}

int cnt;
Point tmp[400005];

bool cmp2(Point A, Point B) {
    return A.y < B.y;
}

long long f(int l, int r) {
    if (l == r) return INF;
    int mid = l + r >> 1;
    long long minn1 = f(l, mid);
    long long minn2 = f(mid + 1, r);
    long long minD = min(minn1, minn2);
    cnt = 0;
    for (int i = l; i <= r; i++) {
        if (llabs(P[mid].x - P[i].x) < minD) {
            tmp[++cnt] = P[i];
        }
    }
    sort(tmp + 1, tmp + cnt + 1, cmp2);
    for (int i = 1; i <= cnt; i++) {
        for (int j = i + 1; j <= cnt && tmp[j].y - tmp[i].y < minD; j++) {
            minD = min(minD, (tmp[i].x - tmp[j].x) * (tmp[i].x - tmp[j].x) + (tmp[i].y - tmp[j].y) * (tmp[i].y - tmp[j].y));
        }
    }
    return minD;
}

int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%lld %lld", &P[i].x, &P[i].y);
    }
    sort(P + 1, P + n + 1, cmp1);
    printf("%.4lf\n", (double)(sqrt(f(1, n))));
    return 0;
}