Problem p00170 (C++)

Buggy submission (status: Time Limit Exceeded):

// include
//------------------------------------------
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)

// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int DX[] = {0, 1, 0, -1};
const int DY[] = {-1, 0, 1, 0};

// clear memory
#define CLR(a) memset((a), 0, sizeof(a))

// debug
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \
       << " " << __FILE__ << endl;

struct Food {
  string name;
  int w;
  int s;
  int id;
  Food(string name, int w, int s, int id) : name(name), w(w), s(s), id(id){};

  bool operator<(const Food &rhs) const { return id < rhs.id; }
};

double calc(vector<Food> foods) {
  int length = foods.size();
  int sum = 0;
  for (int i = length - 1; i >= 0; --i) {
    int s = foods[i].s;
    if (s < sum)
      return DBL_MAX;
    sum += foods[i].w;
  }
  double d = 0, n = 0;
  REP(i, length) {
    n += (i + 1) * foods[i].w;
    d += foods[i].w;
  }
  return n / d;
}

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

  int n;
  vector<Food> ans;
  while (cin >> n, n) {
    vector<Food> foods;
    foods.reserve(n);
    string name;
    int w, s;
    REP(i, n) {
      cin >> name >> w >> s;
      foods.emplace_back(name, w, s, i);
    }
    double min = DBL_MAX;
    do {
      double value = calc(foods);
      if (min > value) {
        min = value;
        ans = foods;
      }
    } while (next_permutation(foods.begin(), foods.end()));
    REP(i, n)
    cout << ans[i].name << endl;
  };
  return 0;
}

Fixed submission:

// include
//------------------------------------------
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define SZ(a) int((a).size())
#define EACH(i, c)                                                             \
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)

// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int DX[] = {0, 1, 0, -1};
const int DY[] = {-1, 0, 1, 0};

// clear memory
#define CLR(a) memset((a), 0, sizeof(a))

// debug
#define dump(x) cerr << #x << " = " << (x) << endl;
#define debug(x)                                                               \
  cerr << #x << " = " << (x) << " (L" << __LINE__ << ")"                       \
       << " " << __FILE__ << endl;

struct Food {
  string name;
  int w;
  int s;
  int id;
  Food(string name, int w, int s, int id) : name(name), w(w), s(s), id(id){};

  bool operator<(const Food &rhs) const { return id < rhs.id; }
};

double calc(vector<Food> &foods) {
  int length = foods.size();
  int sum = 0;
  for (int i = length - 1; i >= 0; --i) {
    int s = foods[i].s;
    if (s < sum)
      return DBL_MAX;
    sum += foods[i].w;
  }
  double d = 0, n = 0;
  REP(i, length) {
    n += (i + 1) * foods[i].w;
    d += foods[i].w;
  }
  return n / d;
}

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

  int n;
  vector<Food> ans;
  while (cin >> n, n) {
    vector<Food> foods;
    foods.reserve(n);
    string name;
    int w, s;
    REP(i, n) {
      cin >> name >> w >> s;
      foods.emplace_back(name, w, s, i);
    }
    double min = DBL_MAX;
    do {
      double value = calc(foods);
      if (min > value) {
        min = value;
        ans = foods;
      }
    } while (next_permutation(foods.begin(), foods.end()));
    REP(i, n)
    cout << ans[i].name << endl;
  };
  return 0;
}