Problem p00452 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
// #define LOG(...)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define RSORT(c) sort((c).rbegin(), (c).rend())
#define CLR(a) memset((a), 0, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

int main() {
  int n, m;
  while (cin >> n >> m, n) {
    vector<int> point(n);
    REP(i, n) { cin >> point[i]; }
    point.push_back(0);
    vector<int> sum = point;
    REP(i, n + 1) {
      REP(j, n + 1) {
        if (count(sum.begin(), sum.end(), sum[i] + sum[j]) == 0)
          sum.push_back(sum[i] + sum[j]);
      }
    }
    SORT(sum);
    int ma = 0;
    REP(i, sum.size()) {
      int left = 0;
      int right = sum.size() - 1;
      while (left < right) {
        if (sum[left + (right - left) / 2] + sum[i] <= m) {
          ma = max(sum[left + (right - left) / 2] + sum[i], ma);
          left = left + (right - left) / 2 + 1;

        } else {
          right = left + (right - left) / 2 - 1;
        }
      }
    }
    cout << ma << endl;
  }
}

Fixed submission:
#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
// #define LOG(...)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define RSORT(c) sort((c).rbegin(), (c).rend())
#define CLR(a) memset((a), 0, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

int main() {
  int n, m;
  while (cin >> n >> m, n) {
    vector<int> point(n);
    REP(i, n) { cin >> point[i]; }
    point.push_back(0);
    vector<int> sum = point;
    REP(i, n + 1) {
      REP(j, n + 1) { sum.push_back(sum[i] + sum[j]); }
    }
    SORT(sum);
    int ma = 0;
    REP(i, sum.size()) {
      int left = 0;
      int right = sum.size() - 1;
      while (left < right) {
        if (sum[left + (right - left) / 2] + sum[i] <= m) {
          ma = max(sum[left + (right - left) / 2] + sum[i], ma);
          left = left + (right - left) / 2 + 1;

        } else {
          right = left + (right - left) / 2 - 1;
        }
      }
    }
    cout << ma << endl;
  }
}