Language: C++

#include <bits/stdc++.h>
// created [2020/01/18] 18:32:54
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"

using i32   = int32_t;
using i64   = int64_t;
using u32   = uint32_t;
using u64   = uint64_t;
using uint  = unsigned int;
using usize = std::size_t;
using ll    = long long;
using ull   = unsigned long long;
using ld    = long double;
template<typename T, usize n>
using arr = T (&)[n];
template<typename T, usize n>
using c_arr = const T (&)[n];
template<typename T> constexpr T popcount(const T u) { return u ? static_cast<T>(__builtin_popcountll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T log2p1(const T u) { return u ? static_cast<T>(64 - __builtin_clzll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T msbp1(const T u) { return log2p1(u); }
template<typename T> constexpr T lsbp1(const T u) { return __builtin_ffsll(u); }
template<typename T> constexpr T clog(const T u) { return u ? log2p1(u - 1) : static_cast<T>(u); }
template<typename T> constexpr bool ispow2(const T u) { return u and (static_cast<u64>(u) & static_cast<u64>(u - 1)) == 0; }
template<typename T> constexpr T ceil2(const T u) { return static_cast<T>(1) << clog(u); }
template<typename T> constexpr T floor2(const T u) { return u == 0 ? static_cast<T>(0) : static_cast<T>(1) << (log2p1(u) - 1); }
template<typename T> constexpr bool btest(const T mask, const usize ind) { return static_cast<bool>((static_cast<u64>(mask) >> ind) & static_cast<u64>(1)); }
template<typename T> void bset(T& mask, const usize ind) { mask |= (static_cast<T>(1) << ind); }
template<typename T> void breset(T& mask, const usize ind) { mask &= ~(static_cast<T>(1) << ind); }
template<typename T> void bflip(T& mask, const usize ind) { mask ^= (static_cast<T>(1) << ind); }
template<typename T> void bset(T& mask, const usize ind, const bool b) { (b ? bset(mask, ind) : breset(mask, ind)); }
template<typename T> constexpr T bcut(const T mask, const usize ind) { return ind == 0 ? static_cast<T>(0) : static_cast<T>((static_cast<u64>(mask) << (64 - ind)) >> (64 - ind)); }
template<typename T> bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template<typename T> bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
constexpr unsigned int mod                  = 1000000007;
template<typename T> constexpr T inf_v      = std::numeric_limits<T>::max() / 4;
template<typename Real> constexpr Real pi_v = Real{3.141592653589793238462643383279502884};
auto mfp = [](auto&& f) { return [=](auto&&... args) { return f(f, std::forward<decltype(args)>(args)...); }; };

template<typename T>
T in()
{
    T v;
    return std::cin >> v, v;
}
template<typename T, typename Uint, usize n, usize i>
T in_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type) { return in<T>(); }
template<typename T, typename Uint, usize n, usize i>
auto in_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type& szs)
{
    const usize s = (usize)szs[i];
    std::vector<decltype(in_v<T, Uint, n, i + 1>(szs))> ans(s);
    for (usize j = 0; j < s; j++) { ans[j] = in_v<T, Uint, n, i + 1>(szs); }
    return ans;
}
template<typename T, typename Uint, usize n>
auto in_v(c_arr<Uint, n> szs) { return in_v<T, Uint, n, 0>(szs); }
template<typename... Types>
auto in_t() { return std::tuple<std::decay_t<Types>...>{in<Types>()...}; }
struct io_init
{
    io_init()
    {
        std::cin.tie(nullptr), std::ios::sync_with_stdio(false);
        std::cout << std::fixed << std::setprecision(20);
    }
    void clear()
    {
        std::cin.tie(), std::ios::sync_with_stdio(true);
    }
} io_setting;

int out() { return 0; }
template<typename T>
int out(const T& v) { return std::cout << v, 0; }
template<typename T>
int out(const std::vector<T>& v)
{
    for (usize i = 0; i < v.size(); i++) {
        if (i > 0) { std::cout << ' '; }
        out(v[i]);
    }
    return std::cout << "\n", 0;
}
template<typename T1, typename T2>
int out(const std::pair<T1, T2>& v) { return out(v.first), std::cout << ' ', out(v.second), 0; }
template<typename T, typename... Args>
int out(const T& v, const Args... args) { return out(v), std::cout << ' ', out(args...), 0; }
template<typename... Args>
int outln(const Args... args) { return out(args...), std::cout << '\n', 0; }
template<typename... Args>
void outel(const Args... args) { return out(args...), std::cout << std::endl, 0; }
#    define SHOW(...) static_cast<void>(0)
constexpr ull TEN(const usize n) { return n == 0 ? 1ULL : TEN(n - 1) * 10ULL; }

template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type, const T& v = T{}) { return v; }
template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type szs, const T& v = T{})
{
    const usize s = (usize)szs[i];
    return std::vector<decltype(make_v<T, Uint, n, i + 1>(szs, v))>(s, make_v<T, Uint, n, i + 1>(szs, v));
}
template<typename T, typename Uint, usize n>
auto make_v(c_arr<Uint, n> szs, const T& t = T{}) { return make_v<T, Uint, n, 0>(szs, t); }
using P      = std::complex<ld>;
using G      = std::vector<P>;
const ld pi  = std::acos(-1);
const ld eps = 1e-10;
const ld inf = 1e12;

ld cross(const P& a, const P& b) { return a.real() * b.imag() - a.imag() * b.real(); }
ld dot(const P& a, const P& b) { return a.real() * b.real() + a.imag() * b.imag(); }

/*
                    CCW

 -- BEHIND -- [a -- ON -- b] --- FRONT --

                    CW
enum CCW_RESULT { CCW    = +1,
                  CW     = -1,
                  BEHIND = +2,
                  FRONT  = -2,
                  ON     = 0 };
int ccw(P a, P b, P c)
{
    b -= a;
    c -= a;
    if (cross(b, c) > eps) return CCW;    // counter clockwise
    if (cross(b, c) < -eps) return CW;    // clockwise
    if (dot(b, c) < 0) return BEHIND;     // c--a--b on line
    if (norm(b) < norm(c)) return FRONT;  // a--b--c on line
    return ON;
}

namespace std {
bool operator<(const P& a, const P& b)
{
    return std::abs(real(a) - real(b)) > eps ? real(a) < real(b) : imag(a) < imag(b);
}
}  // namespace std

struct L : public std::vector<P>
{
    L(const P& a = P(), const P& b = P()) : std::vector<P>(2)
    {
        begin()[0] = a;
        begin()[1] = b;
    }

    // Ax + By + C = 0
    L(ld A, ld B, ld C)
    {
        if (std::abs(A) < eps && std::abs(B) < eps) {
            abort();
        } else if (std::abs(A) < eps) {
            *this = L(P(0, -C / B), P(1, -C / B));
        } else if (std::abs(B) < eps) {
            *this = L(P(-C / A, 0), P(-C / A, 1));
        } else {
            *this = L(P(0, -C / B), P(-C / A, 0));
        }
    }
};

struct C
{
    P p;
    ld r;
    C(const P& p = 0, ld r = 0) : p(p), r(r) {}
};
template<class iter>
std::pair<P, ld> min_ball(iter left, iter right, int seed = 1333)
{
    const int n = right - left;

    assert(n >= 1);
    if (n == 1) {
        return {*left, ld(0)};
    }

    std::mt19937 mt(seed);
    std::shuffle(left, right, mt);
    // std::random_shuffle(left, right); // simple but deprecated

    iter ps      = left;
    using circle = std::pair<P, ld>;

    auto make_circle_3 = [](const P& a, const P& b, const P& c) -> circle {
        ld A = std::norm(b - c), B = std::norm(c - a), C = std::norm(a - b),
           S  = cross(b - a, c - a);
        P p   = (A * (B + C - A) * a + B * (C + A - B) * b + C * (A + B - C) * c) / (4 * S * S);
        ld r2 = std::norm(p - a);
        return {p, r2};
    };

    auto make_circle_2 = [](const P& a, const P& b) -> circle {
        P c   = (a + b) / (ld)2;
        ld r2 = std::norm(a - c);
        return {c, r2};
    };

    auto in_circle = [](const P& a, const circle& c) -> bool {
        return std::norm(a - c.first) <= c.second + eps;
    };

    circle c = make_circle_2(ps[0], ps[1]);

    // MiniDisc
    for (int i = 2; i < n; ++i) {
        if (!in_circle(ps[i], c)) {
            // MiniDiscWithPoint
            c = make_circle_2(ps[0], ps[i]);
            for (int j = 1; j < i; ++j) {
                if (!in_circle(ps[j], c)) {
                    // MiniDiscWith2Points
                    c = make_circle_2(ps[i], ps[j]);
                    for (int k = 0; k < j; ++k) {
                        if (!in_circle(ps[k], c)) {
                            c = make_circle_3(ps[i], ps[j], ps[k]);
                        }
                    }
                }
            }
        }
    }
    return c;
}
int main()
{
    const auto N = in<int>();
    std::vector<P> p(N);
    for (int i = 0; i < N; i++) {
        const auto y = in<ld>(), x = in<ld>();
        p[i] = {y, x};
    }
    const auto ans = min_ball(p.begin(), p.end());
    outln(std::sqrt(ans.second));
    return 0;
}


Compiler output:
a.cc:115:1: error: unterminated comment
  115 | /*
      | ^