My answer-programs submitted to online-judge and got TLE.

poj1027.cc

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>
#include <utility>
using namespace std;

typedef vector<vector<char> > B;
typedef pair<int, int> P;

int dc[] = {0, 1, 0, -1};
int dr[] = {1, 0, -1, 0};

bool visited[15][10];

bool inner(B& b, int c, int r) {
  return 0 <= c && c < b.size() && 0 <= r && r < b[c].size();
}

vector<P> cluster(B& b, int c, int r, char col) {

  vector<P> res(0);

  if (!inner(b, c, r) || b[c][r] != col || visited[c][r]) return res;

  visited[c][r] = true;

  res.push_back(P(c, r));
  for (int i = 0; i < 4; i++) {
    int nc = c + dc[i], nr = r + dr[i];
    vector<P> rest_mem = cluster(b, nc, nr, col);
    res.insert(res.end(), rest_mem.begin(), rest_mem.end());
  }

  return res;
}

void fall(vector<char>& v) {
  while (find(v.begin(), v.end(), 0) != v.end())
    v.erase(find(v.begin(), v.end(), 0));
}

void pack(B& v) {
  for (int i = 0; i < v.size(); i++)
    if (v[i].size() == 0)
      v.erase(v.begin() + i--);
}

int main() {

  int CASES;
  cin >> CASES;

  for (int case_num = 1; case_num <= CASES; case_num++) {

    printf("Game %d:\n\n", case_num);
    
    B b(15, vector<char>(10));

    for (int i = 9; i >= 0; i--)
      for (int j = 0; j < 15; j++)
	cin >> b[j][i];

    int remain_balls = 150, total_score = 0, move_num = 1;
    while (remain_balls > 0) {

      memset(visited, false, sizeof(visited));

      vector<P> max_member;
      for (int c = 0; c < b.size(); c++) {
	for (int r = 0; r < b[c].size(); r++) {

	  vector<P> clus_member = cluster(b, c, r, b[c][r]);

	  if (clus_member.size() > max_member.size())
	    max_member = clus_member;
	}
      }

      int n = max_member.size(), c = max_member[0].first, r = max_member[0].second;
      char col = b[c][r];

      if (n == 1) break;
      
      for (int i = 0; i < n; i++) 
	b[max_member[i].first][max_member[i].second] = 0;

      for (int i = 0; i < b.size(); i++)
	fall(b[i]);

      pack(b);

      printf("Move %d at (%d, %d): removed %d balls of color %c, got %d points.\n",
	     move_num++, r + 1, c + 1, n, col, (2 - n) * (2 - n));
      
      remain_balls -= n;
      total_score  += (2 - n) * (2 - n);
    }

    if (remain_balls == 0) total_score += 1000;
    printf("Final score: %d, with %d balls remaining.\n\n", total_score, remain_balls);
  }
}