Problem p01414 (C++) — buggy submission, verdict: Time Limit Exceeded

// include
//------------------------------------------
#include <algorithm>
#include <bitset>
#include <cctype>
#include <climits>
#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;

// 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 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);

int N, bd[1 << 16];
int H[16], W[16];
VS orig(4);

int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  cin >> N;
  REP(i, N) cin >> H[i] >> W[i];
  REP(i, 4) cin >> orig[i];

  vector<PII> trans[16];
  REP(i, N) {
    for (int y = -H[i] + 1; y < 4; ++y) {
      for (int x = -W[i] + 1; x < 4; ++x) {
        for (int k = 0; k < 3; ++k) {
          int tmp1 = 0, tmp2 = (1 << 16) - 1;
          char c = "RGB"[k];
          for (int dy = 0; dy < H[i]; ++dy) {
            int ty = y + dy;
            if (ty < 0 || 4 <= ty)
              continue;
            for (int dx = 0; dx < W[i]; ++dx) {
              int tx = x + dx;
              if (tx < 0 || 4 <= tx)
                continue;
              if (c == orig[ty][tx])
                tmp1 |= (1 << (ty * 4 + tx));
              else
                tmp2 &= ~(1 << (ty * 4 + tx));
            }
          }
          trans[i].PB(MP(tmp1, tmp2));
        }
      }
    }
  }

  priority_queue<PII, vector<PII>, greater<PII>> pq;
  fill(bd, bd + (1 << 16), 1000);
  bd[0] = 0;
  pq.push(MP(0, 0));
  while (!pq.empty()) {
    PII pii = pq.top();
    pq.pop();
    int ct = pii.first;
    int state = pii.second;
    if (ct > bd[state])
      continue;

    REP(i, 16) {
      for (PII &pii : trans[i]) {
        int tmp = state;
        tmp |= pii.first;
        tmp &= pii.second;
        if (bd[tmp] > ct + 1) {
          bd[tmp] = ct + 1;
          pq.push(MP(bd[tmp], tmp));
        }
      }
    }
  }

  cout << bd[(1 << 16) - 1] << endl;

  return 0;
}

Error: TLE

Fixed submission:

// include
//------------------------------------------
#include <algorithm>
#include <bitset>
#include <cctype>
#include <climits>
#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;

// 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 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);

int N, bd[1 << 16];
int H[16], W[16];
VS orig(4);

int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  cin >> N;
  REP(i, N) cin >> H[i] >> W[i];
  REP(i, 4) cin >> orig[i];

  priority_queue<PII, vector<PII>, greater<PII>> pq;
  fill(bd, bd + (1 << 16), 1000);
  bd[0] = 0;
  pq.push(MP(0, 0));
  while (!pq.empty()) {
    PII pii = pq.top();
    pq.pop();
    int ct = pii.first;
    int state = pii.second;
    if (ct > bd[state])
      continue;

    REP(i, N) {
      for (int y = -H[i] + 1; y < 4; ++y) {
        for (int x = -W[i] + 1; x < 4; ++x) {
          for (int k = 0; k < 3; ++k) {
            char c = "RGB"[k];
            int tmp = state;
            for (int dy = 0; dy < H[i]; ++dy) {
              int ty = y + dy;
              if (ty < 0 || 4 <= ty)
                continue;
              for (int dx = 0; dx < W[i]; ++dx) {
                int tx = x + dx;
                if (tx < 0 || 4 <= tx)
                  continue;
                //			  if(c == ' ') c = orig[ty][tx];
                if (c == orig[ty][tx])
                  tmp = tmp | (1 << (ty * 4 + tx));
                else
                  tmp = tmp & ~(1 << (ty * 4 + tx));
              }
            }
            if (bd[tmp] > ct + 1) {
              bd[tmp] = ct + 1;
              pq.push(MP(bd[tmp], tmp));
            }
          }
        }
      }
    }
  }

  cout << bd[(1 << 16) - 1] << endl;

  return 0;
}