Problem p03221 (C++)

Buggy submission (status: Time Limit Exceeded):

// include
//------------------------------------------
#include <algorithm>
#include <bitset>
#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 <queue>
#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 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 EXISTch(s, c)                                                          \
  ((((s).find_first_of(c)) != std::string::npos) ? 1 : 0) // cがあれば1 if(1)
#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)
#define loop(n) FOR(i, 0, n)
#define rrep(i, a, b) for (int i = (a); i >= (b); --i)
// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int INF = (int)1000000007;
const LL MOD = (LL)1000000007;          // 10^9+7
const LL INF2 = (LL)100000000000000000; // 10^18

int main() {
  int n, m;
  cin >> n >> m;

  vector<vector<int>> tb(n);
  vector<int> p(m);
  vector<int> y(m);
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    p[i] = a;
    y[i] = b;

    tb[a].push_back(b);
  }

  for (int i = 0; i < n; i++) {
    sort(tb[i].begin(), tb[i].end());
  }

  for (int i = 0; i < m; i++) {
    cout << setfill('0') << setw(6) << p[i] + 1;
    auto itr = find(tb[p[i]].begin(), tb[p[i]].end(), y[i]);

    int rank = itr - tb[p[i]].begin() + 1;

    cout << setfill('0') << setw(6) << rank << endl;
  }
}

Fixed submission:

// include
//------------------------------------------
#include <algorithm>
#include <bitset>
#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 <queue>
#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 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 EXISTch(s, c)                                                          \
  ((((s).find_first_of(c)) != std::string::npos) ? 1 : 0) // cがあれば1 if(1)
#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)
#define loop(n) FOR(i, 0, n)
#define rrep(i, a, b) for (int i = (a); i >= (b); --i)
// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int INF = (int)1000000007;
const LL MOD = (LL)1000000007;          // 10^9+7
const LL INF2 = (LL)100000000000000000; // 10^18

int main() {
  int n, m;
  cin >> n >> m;

  vector<vector<int>> tb(n);
  vector<int> p(m);
  vector<int> y(m);
  for (int i = 0; i < m; i++) {
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    p[i] = a;
    y[i] = b;

    tb[a].push_back(b);
  }

  for (int i = 0; i < n; i++) {
    sort(tb[i].begin(), tb[i].end());
  }

  for (int i = 0; i < m; i++) {
    cout << setfill('0') << setw(6) << p[i] + 1;
    auto itr = lower_bound(tb[p[i]].begin(), tb[p[i]].end(), y[i]);

    int rank = itr - tb[p[i]].begin() + 1;

    cout << setfill('0') << setw(6) << rank << endl;
  }
}