Problem p02608 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <vector>

using namespace std;

#define DEBUG_ //!!$BDs=P;~$K%3%a%s%H%"%&%H(B!!
#ifdef DEBUG_
#define dump(x) cerr << #x << " = " << (x) << endl;
#else
#define dump(x) ;
#endif

#define equals(a, b) (fabs((a) - (b)) < EPS)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back

// #define int long long

typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;

template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

template <typename T> std::string printVector(const std::vector<T> &data) {
  std::stringstream ss;
  std::ostream_iterator<T> out_it(ss, ", ");
  ss << "[";
  std::copy(data.begin(), data.end() - 1, out_it);
  ss << data.back() << "]";
  return ss.str();
}

template <typename T> void print_array(const T &ary, int size) {
  REP(i, size) { cout << ary[i] << " "; }
  cout << endl;
}

const int mod = 1e9 + 7;
const LL LINF = 1001002003004005006ll;
const int INF = 1001001001;
const double EPS = (1e-10);
const long double PI =
    3.14159265358979323846264338327950288419716939937510582097494459230781640628620899;
int dx[] = {0, 0, -1, 1};
int dy[] = {-1, 1, 0, 0};

signed main(int argc, char const *argv[]) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(12);

  LL N;
  cin >> N;
  FOR(n, 1, N + 1) {
    LL ans = 0;
    for (LL i = 1; i * i <= n; i++) {
      for (LL j = 1; j * j <= (n - i * i); j++) {
        LL sqr = (i + j) * (i + j) - 4 * (i * j + i * i + j * j) + 4 * n;
        if (sqr <= 0)
          continue;
        LL ng = 0, ok = 10010;
        while (abs(ok - ng) > 1) {
          LL mid = (ok + ng) / 2;
          if (mid * mid >= sqr)
            ok = mid;
          else
            ng = mid;
        }
        if (ok * ok != sqr)
          continue;
        LL tmp = ok - i - j;
        if (tmp <= 0 or tmp % 2 == 1)
          continue;
        ans++;
      }
    }
    cout << ans << endl;
  }
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <vector>

using namespace std;

#define DEBUG_ //!!$BDs=P;~$K%3%a%s%H%"%&%H(B!!
#ifdef DEBUG_
#define dump(x) cerr << #x << " = " << (x) << endl;
#else
#define dump(x) ;
#endif

#define equals(a, b) (fabs((a) - (b)) < EPS)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back

// #define int long long

typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;

template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

template <typename T> std::string printVector(const std::vector<T> &data) {
  std::stringstream ss;
  std::ostream_iterator<T> out_it(ss, ", ");
  ss << "[";
  std::copy(data.begin(), data.end() - 1, out_it);
  ss << data.back() << "]";
  return ss.str();
}

template <typename T> void print_array(const T &ary, int size) {
  REP(i, size) { cout << ary[i] << " "; }
  cout << endl;
}

const int mod = 1e9 + 7;
const LL LINF = 1001002003004005006ll;
const int INF = 1001001001;
const double EPS = (1e-10);
const long double PI =
    3.14159265358979323846264338327950288419716939937510582097494459230781640628620899;
int dx[] = {0, 0, -1, 1};
int dy[] = {-1, 1, 0, 0};

signed main(int argc, char const *argv[]) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(12);

  LL N;
  cin >> N;
  FOR(n, 1, N + 1) {
    LL ans = 0;
    for (LL i = 1; i * i <= n; i++) {
      for (LL j = 1; j * j <= (n - i * i); j++) {
        for (LL k = 1; k * k <= (n - i * i - j * j); k++) {
          if (i * i + j * j + k * k + i * j + j * k + k * i == n)
            ans++;
        }
      }
    }
    cout << ans << endl;
  }
}