Problem p02690 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<long long> vll;
#define left(x) (x << 1)
#define right(x) (x << 1) + 1
#define mid(l, r) ((l + r) >> 1)
#define mp make_pair
#define pb push_back
#define all(a) a.begin(), a.end()
#define debug(x)                                                               \\
  { cerr << #x << " = " << x << "\\n"; }
#define debug2(x, y)                                                           \\
  { cerr << #x << " = " << x << ", " << #y << " = " << y << "\\n"; }
#define debug3(x, y, z)                                                        \\
  {                                                                            \\
    cerr << #x << " = " << x << ", " << #y << " = " << y << ", " << #z         \\
         << " = " << z << "\\n";                                                \\
  }
#define debug4(x, y, z, w)                                                     \\
  {                                                                            \\
    cerr << #x << " = " << x << ", " << #y << " = " << y << ", " << #z         \\
         << " = " << z << ", " << #w << " = " << w << "\\n";                    \\
  }
#define ss second
#define ff first
#define m0(x) memset(x, 0, sizeof(x))

template <typename T> T min_(T a, T b) { return a > b ? b : a; }
template <typename T, typename... Ts> T min_(T first, Ts... last) {
  return min_(first, min_(last...));
}
template <typename T> T max_(T a, T b) { return a > b ? a : b; }
template <typename T, typename... Ts> T max_(T first, Ts... last) {
  return max_(first, min_(last...));
}

template <class T, class S>
std::ostream &operator<<(std::ostream &os, const std::pair<T, S> &t) {
  os << "(" << t.first << ", " << t.second << ")";
  return os;
}
template <typename T> ostream &operator<<(ostream &out, const vector<T> &v) {
  out << "[";
  size_t last = v.size() - 1;
  for (size_t i = 0; i < v.size(); ++i) {
    out << v[i];
    if (i != last)
      out << ", ";
  }
  out << "]";
  return out;
}
const int mod = 1e9 + 7;

ll pwr(ll base, ll p) {
  ll ans = 1;
  while (p) {
    if (p & 1)
      ans = (ans * base) % mod;
    base = (base * base) % mod;
    p /= 2;
  }
  return ans;
}
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
ll lcm(ll a, ll b) { return a * (b / gcd(a, b)); }

const long double PI = (long double)(3.1415926535897932384626433832795);
const ll mx_ll = numeric_limits<ll>::max();
const int mx_int = numeric_limits<int>::max();

const int maxn = 1e6;

double nthRoot(int A, int N) {
  double xPre = rand() % 10;
  double eps = 1e-3;
  double delX = mx_int;
  double xK;
  while (delX > eps) {
    xK = ((N - 1.0) * xPre + (double)A / pow(xPre, N - 1)) / (double)N;
    delX = abs(xK - xPre);
    xPre = xK;
  }
  return xK;
}

const double EPS = 0.000001;
bool double_is_int(double trouble) {
  double absolute = abs(trouble);
  // debug2(absolute, floor(absolute));
  return (fabs(absolute - floor(absolute)) < EPS);
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);

  map<ll, pll> mp;
  for (ll a = -500; a <= 500; ++a) {
    for (ll b = -500; b <= 500; ++b) {
      ll a5 = a * a * a * a * a;
      ll b5 = b * b * b * b * b;
      mp[a5 - b5] = {a, b};
    }
  }
  ll X;
  cin >> X;
  if (mp.find(X) != mp.end()) {
    cout << mp[X].ff << " " << mp[X].ss << endl;
    return 0;
  }
  for (ll i = 0; i <= 1000; ++i) {
    ll a5 = i * i * i * i * i;
    ll t2 = a5 - X;
    double b = nthRoot(t2, 5);
    // debug3(a5,t2,b);
    // debug(double_is_int(b));
    if (double_is_int(b)) {
      cout << i << " " << b << endl;
      return 0;
    }
  }
  for (ll i = 0; i >= -1000; --i) {
    ll a5 = i * i * i * i * i;
    ll t2 = a5 - X;
    double b = nthRoot(t2, 5);
    // debug3(a5,t2,b);
    // debug(double_is_int(b));
    if (double_is_int(b)) {
      cout << i << " " << b << endl;
      return 0;
    }
  }
  assert(X == -1);
  // cout << a << " " << b << endl;
  return 0;
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<long long> vll;
#define left(x) (x << 1)
#define right(x) (x << 1) + 1
#define mid(l, r) ((l + r) >> 1)
#define mp make_pair
#define pb push_back
#define all(a) a.begin(), a.end()
#define debug(x)                                                               \\
  { cerr << #x << " = " << x << "\\n"; }
#define debug2(x, y)                                                           \\
  { cerr << #x << " = " << x << ", " << #y << " = " << y << "\\n"; }
#define debug3(x, y, z)                                                        \\
  {                                                                            \\
    cerr << #x << " = " << x << ", " << #y << " = " << y << ", " << #z         \\
         << " = " << z << "\\n";                                                \\
  }
#define debug4(x, y, z, w)                                                     \\
  {                                                                            \\
    cerr << #x << " = " << x << ", " << #y << " = " << y << ", " << #z         \\
         << " = " << z << ", " << #w << " = " << w << "\\n";                    \\
  }
#define ss second
#define ff first
#define m0(x) memset(x, 0, sizeof(x))

template <typename T> T min_(T a, T b) { return a > b ? b : a; }
template <typename T, typename... Ts> T min_(T first, Ts... last) {
  return min_(first, min_(last...));
}
template <typename T> T max_(T a, T b) { return a > b ? a : b; }
template <typename T, typename... Ts> T max_(T first, Ts... last) {
  return max_(first, min_(last...));
}

template <class T, class S>
std::ostream &operator<<(std::ostream &os, const std::pair<T, S> &t) {
  os << "(" << t.first << ", " << t.second << ")";
  return os;
}
template <typename T> ostream &operator<<(ostream &out, const vector<T> &v) {
  out << "[";
  size_t last = v.size() - 1;
  for (size_t i = 0; i < v.size(); ++i) {
    out << v[i];
    if (i != last)
      out << ", ";
  }
  out << "]";
  return out;
}
const int mod = 1e9 + 7;

ll pwr(ll base, ll p) {
  ll ans = 1;
  while (p) {
    if (p & 1)
      ans = (ans * base) % mod;
    base = (base * base) % mod;
    p /= 2;
  }
  return ans;
}
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
ll lcm(ll a, ll b) { return a * (b / gcd(a, b)); }

const long double PI = (long double)(3.1415926535897932384626433832795);
const ll mx_ll = numeric_limits<ll>::max();
const int mx_int = numeric_limits<int>::max();

const int maxn = 1e6;

double nthRoot(int A, int N) {
  double xPre = rand() % 10;
  double eps = 1e-3;
  double delX = mx_int;
  double xK;
  while (delX > eps) {
    xK = ((N - 1.0) * xPre + (double)A / pow(xPre, N - 1)) / (double)N;
    delX = abs(xK - xPre);
    xPre = xK;
  }
  return xK;
}

const double EPS = 0.000001;
bool double_is_int(double trouble) {
  double absolute = abs(trouble);
  // debug2(absolute, floor(absolute));
  return (fabs(absolute - floor(absolute)) < EPS);
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);

  map<ll, pll> mp;
  for (ll a = -1000; a <= 1000; ++a) {
    for (ll b = -1000; b <= 1000; ++b) {
      ll a5 = a * a * a * a * a;
      ll b5 = b * b * b * b * b;
      mp[a5 - b5] = {a, b};
    }
  }
  ll X;
  cin >> X;
  if (mp.find(X) != mp.end()) {
    cout << mp[X].ff << " " << mp[X].ss << endl;
    return 0;
  }
  for (ll i = 0; i <= 1000; ++i) {
    ll a5 = i * i * i * i * i;
    ll t2 = a5 - X;
    double b = nthRoot(t2, 5);
    // debug3(a5,t2,b);
    // debug(double_is_int(b));
    if (double_is_int(b)) {
      cout << i << " " << b << endl;
      return 0;
    }
  }
  for (ll i = 0; i >= -1000; --i) {
    ll a5 = i * i * i * i * i;
    ll t2 = a5 - X;
    double b = nthRoot(t2, 5);
    // debug3(a5,t2,b);
    // debug(double_is_int(b));
    if (double_is_int(b)) {
      cout << i << " " << b << endl;
      return 0;
    }
  }
  assert(X == -1);
  // cout << a << " " << b << endl;
  return 0;
}