Problem p01137 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <bitset>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

typedef unsigned int UI;
typedef long long LL;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef istringstream ISS;
typedef ostringstream OSS;

const int INF = INT_MAX / 4;
const double EPS = 1e-12;

#define REP(i, m, n) for (int i = (int)(m); i < (int)(n); ++i)
#define EACH(v, c) for (auto &v : c)

#define ITER(c) __typeof((c).begin())
#define IREP(c, it) for (ITER(c) it = c.begin(); it != c.end(); ++it)
#define ALL(c) (c).begin(), (c).end()

#define PB(n) push_back(n)
#define MP(a, b) make_pair((a), (b))
#define EXIST(c, e) ((c).find(e) != (c).end())

#define fst first
#define snd second

#define DUMP(x) cerr << #x << " = " << (x) << endl
#define DEBUG(x)                                                               \
  cerr << __FILE__ << ":" << __LINE__ << ": " << #x << " = " << (x) << endl

int main() {
  while (true) {
    int e;
    cin >> e;

    if (!e) {
      break;
    }

    ULL min = INT_MAX;

    for (ULL x = 0; x <= e; x++) {
      for (ULL y = 0; y * y <= e; y++) {
        for (ULL z = 0; z * z * z <= e; z++) {
          if (x + y * y + z * z * z == e) {
            min = std::min(min, x + y + z);
          }
        }
      }
    }

    cout << min << endl;
  }

  return 0;
}

Fixed submission:
#include <algorithm>
#include <bitset>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

typedef unsigned int UI;
typedef long long LL;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef istringstream ISS;
typedef ostringstream OSS;

const int INF = INT_MAX / 4;
const double EPS = 1e-12;

#define REP(i, m, n) for (int i = (int)(m); i < (int)(n); ++i)
#define EACH(v, c) for (auto &v : c)

#define ITER(c) __typeof((c).begin())
#define IREP(c, it) for (ITER(c) it = c.begin(); it != c.end(); ++it)
#define ALL(c) (c).begin(), (c).end()

#define PB(n) push_back(n)
#define MP(a, b) make_pair((a), (b))
#define EXIST(c, e) ((c).find(e) != (c).end())

#define fst first
#define snd second

#define DUMP(x) cerr << #x << " = " << (x) << endl
#define DEBUG(x)                                                               \
  cerr << __FILE__ << ":" << __LINE__ << ": " << #x << " = " << (x) << endl

int main() {
  while (true) {
    int e;
    cin >> e;

    if (!e) {
      break;
    }

    ULL min = INT_MAX;

    for (ULL y = 0; y * y <= e; y++) {
      for (ULL z = 0; z * z * z <= e; z++) {
        LL x = e - z * z * z - y * y;

        if (x < 0) {
          break;
        }

        if (x + y * y + z * z * z == e) {
          min = std::min(min, x + y + z);
        }
      }
    }

    cout << min << endl;
  }

  return 0;
}