Problem p00507 (C++) — buggy submission, verdict: Memory Limit Exceeded

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;

#define PI 3.141592653589793238462643383279
#define mod 1000000007LL
#define rep(i, n) for (i = 0; i < n; ++i)
#define rep1(i, n) for (i = 1; i < n; ++i)
#define per(i, n) for (i = n - 1; i > -1; --i)
#define int(x)                                                                 \\
  int x;                                                                       \\
  scanf("%d", &x)
#define int2(x, y)                                                             \\
  int x, y;                                                                    \\
  scanf("%d%d", &x, &y)
#define int3(x, y, z)                                                          \\
  int x, y, z;                                                                 \\
  scanf("%d%d%d", &x, &y, &z)
#define int4(v, x, y, z)                                                       \\
  int v, x, y, z;                                                              \\
  scanf("%d%d%d%d", &v, &x, &y, &z)
#define int5(v, w, x, y, z)                                                    \\
  int v, w, x, y, z;                                                           \\
  scanf("%d%d%d%d%d", &v, &w, &x, &y, &z)
#define ll2(x, y)                                                              \\
  ll x, y;                                                                     \\
  cin >> x >> y;
#define scn(n, a) rep(i, n) cin >> a[i]
#define sc2n(n, a, b) rep(i, n) cin >> a[i] >> b[i]
#define pri(x) cout << (x) << "\\n"
#define pri2(x, y) cout << (x) << " " << (y) << "\\n"
#define pri3(x, y, z) cout << (x) << " " << (y) << " " << (z) << "\\n"
#define pb push_back
#define mp make_pair
#define all(a) (a).begin(), (a).end()
#define endl "\\n"
#define kabe puts("---------------------------")
#define kara puts("")
#define debug(x) cout << " --- " << (x) << "\\n"
#define debug2(x, y) cout << " --- " << (x) << " " << (y) << "\\n"
#define debug3(x, y, z)                                                        \\
  cout << " --- " << (x) << " " << (y) << " " << (z) << "\\n"
#define X first
#define Y second
#define eps 0.0001
#define prid(x) printf("%.15lf\\n", x)

int a[10000];
int res[1000000];

signed main(void) {
  int i, j;
  for (int testcase = 0; testcase >= 0; testcase++) {
    int(n);
    scn(n, a);
    sort(a, a + n);

    int h = 0;
    rep(i, min(n, 10)) {
      int tmp = a[i], d = 1;
      for (;; d *= 10)
        if (a[i] < d)
          break;
      rep(j, n) if (i != j) res[h++] = a[j] * d + a[i];
    }
    sort(res, res + h);
    pri(res[2]);

    /*/

    //*/
    break;
  }
  return 0;
}

Error: MLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;

#define PI 3.141592653589793238462643383279
#define mod 1000000007LL
#define rep(i, n) for (i = 0; i < n; ++i)
#define rep1(i, n) for (i = 1; i < n; ++i)
#define per(i, n) for (i = n - 1; i > -1; --i)
#define int(x)                                                                 \\
  int x;                                                                       \\
  scanf("%d", &x)
#define int2(x, y)                                                             \\
  int x, y;                                                                    \\
  scanf("%d%d", &x, &y)
#define int3(x, y, z)                                                          \\
  int x, y, z;                                                                 \\
  scanf("%d%d%d", &x, &y, &z)
#define int4(v, x, y, z)                                                       \\
  int v, x, y, z;                                                              \\
  scanf("%d%d%d%d", &v, &x, &y, &z)
#define int5(v, w, x, y, z)                                                    \\
  int v, w, x, y, z;                                                           \\
  scanf("%d%d%d%d%d", &v, &w, &x, &y, &z)
#define ll2(x, y)                                                              \\
  ll x, y;                                                                     \\
  cin >> x >> y;
#define scn(n, a) rep(i, n) cin >> a[i]
#define sc2n(n, a, b) rep(i, n) cin >> a[i] >> b[i]
#define pri(x) cout << (x) << "\\n"
#define pri2(x, y) cout << (x) << " " << (y) << "\\n"
#define pri3(x, y, z) cout << (x) << " " << (y) << " " << (z) << "\\n"
#define pb push_back
#define mp make_pair
#define all(a) (a).begin(), (a).end()
#define endl "\\n"
#define kabe puts("---------------------------")
#define kara puts("")
#define debug(x) cout << " --- " << (x) << "\\n"
#define debug2(x, y) cout << " --- " << (x) << " " << (y) << "\\n"
#define debug3(x, y, z)                                                        \\
  cout << " --- " << (x) << " " << (y) << " " << (z) << "\\n"
#define X first
#define Y second
#define eps 0.0001
#define prid(x) printf("%.15lf\\n", x)

int a[10000];
int res[99990001];

signed main(void) {
  int i, j;
  for (int testcase = 0; testcase >= 0; testcase++) {
    int(n);
    scn(n, a);
    sort(a, a + n);

    int h = 0;
    rep(i, n) {
      int tmp = a[i], d = 1;
      for (;; d *= 10)
        if (a[i] < d)
          break;
      rep(j, n) if (i != j) res[h++] = a[j] * d + a[i];
    }
    sort(res, res + h);
    pri(res[2]);

    /*/

    //*/
    break;
  }
  return 0;
}