Problem p02690 (C++) — buggy submission, verdict: Runtime Error

/**
 *    author:  math2do
 *    created: 04.05.2020 03:25:00 IST
 **/

#include <bits/stdc++.h>

using namespace std;

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(const char &ch) { return "'" + string(1, ch) + "'"; }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  reverse(res.begin(), res.end());
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

long long power(int x, int b) {
  long long a = x;
  long long res = 1;
  while (b > 0) {
    if (b & 1) {
      res = res * a;
    }
    b >>= 1;
    a = a * a;
  }
  return res;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long x;
  cin >> x;
  pair<int, int> ans;
  bool found = false;
  for (int a = -1000; a <= 1000; a++) {
    long long A = power(a, 5);
    long long rem = A - x;
    int l = -1000, h = 1000;
    while (l <= h) {
      int m = (l + h) / 2;
      long long B = power(m, 5);
      if (B == rem) {
        found = true;
        ans.first = a;
        ans.second = m;
        goto end;
      } else if (B > rem) {
        h = m - 1;
      } else {
        l = m + 1;
      }
    }
  }
end : {
  assert(found);
  cout << ans.first << " " << ans.second << endl;
}
  return 0;
}


Error: WA

Fixed submission:

/**
 *    author:  math2do
 *    created: 04.05.2020 03:25:00 IST
 **/

#include <bits/stdc++.h>

using namespace std;

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(const char &ch) { return "'" + string(1, ch) + "'"; }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  reverse(res.begin(), res.end());
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

inline long long power(int x, int b) {
  long long a = x;
  long long res = 1;
  while (b > 0) {
    if (b & 1) {
      res = res * a;
    }
    b >>= 1;
    a = a * a;
  }
  return res;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long x;
  cin >> x;
  long long A, B;
  bool found = false;
  for (int a = -100; a <= 100; a++) {
    for (int b = -100; b <= 100; b++) {
      long long res = power(a, 5) - power(b, 5);
      if (res == x) {
        found = true;
        A = a;
        B = b;
        goto end;
      }
    }
  }
end : {
  assert(found);
  cout << A << " " << B << endl;
}
  return 0;
}