Submission #1139698

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Source Code Expand

#include <iostream>
#include <vector>
#include <random>
#include <list>

using namespace std;
// template for creating 2d vector
template<typename T>
vector<vector<T>> make_2d_vector(size_t rows, size_t cols, T init)
{ return vector< vector<T> >(rows, vector<T>(cols, init)); }


typedef vector< vector<int> > two_d_vector;

random_device rnd;


#define debug(x) cout << #x << "==" << x << endl;

const int inf = 100000000;

typedef long long ll;

#define N 30
auto A = make_2d_vector(30, 30, 0);

//移動4方向のベクトル
int di[4] = {1, 0, -1, 0};
int dj[4] = {0, 1,  0, -1};

typedef pair<int,int> P;

bool in_bound(P p) {
  return (p.first < N) && (0 <= p.first) && (p.second < N) && (0 <= p.second);;
}

void print_A() {
  for(int i = 0; i < N; i++) {
    for(int j = 0; j < N; j++) {
      cout << A[i][j] << " ";
    } cout << "\n";
  } cout << "\n";
}

void print_pos(P p) {
  cout << p.first+1 << " " << p.second+1 << "\n";
}

void minus_path(list<P> &lp) {
  for(auto itr = lp.begin(); itr != lp.end(); ++itr) {
    P p = *itr;
    print_pos(p);
    A[p.first][p.second]--;
  }

}

list<P> get_path(P p) {
  int i = p.first; int j = p.second;

  if( A[i][j] == 0 ) {
    list<P> empty;
    return empty;
  }
  list<P> ret;
  ret.push_back( p );

  vector< P > next_cand;
  vector< P > next_same;
  for(int k = 0; k < 4; k++) {
    int ni = i + di[k]; int nj = j + dj[k];
    P np = P(ni, nj);
    if( in_bound(np) ) {
      if( A[ni][nj] == A[i][j]-1 )   next_cand.push_back( np );
      else if (A[ni][nj] == A[i][j]) next_same.push_back( np );
    }
  }

  if( next_cand.size() != 0 ) {
    P np = next_cand[ rnd() % next_cand.size() ];
    list<P> ap = get_path( np );
    ret.splice(ret.end(), ap);
  } // else if( next_same.size() != 0 ) {
  //   P np = next_same[ rnd() % next_cand.size() ];
  //   list<P> ap = get_path( np );
  //   ap.splice(ap.end(), ret);
  //   ret = ap;
  // }

  return ret;

}

P get_max_index() {
  P max_index;
  int max_n = 0;
  for(int i = 0; i < N; i++) {
    for(int j = 0; j < N; j++) {
      int n = A[i][j];
      if(max_n < n) {
        max_index = P(i,j);
        max_n = n;
      } else if (max_n == n) {
        if( rnd() % 2 == 0 )  max_index = P(i,j);
      }
    }
  }
  return max_index;
}

int main() {
  ios::sync_with_stdio(false);

  for(int i = 0; i < N; i++) {
    for(int j = 0; j < N; j++) {
      cin >> A[i][j];
    }
  }


  while(true) {
    P mxp = get_max_index();
    if( A[mxp.first][mxp.second] == 0) { break; }
    list<P> lp = get_path( mxp );
    minus_path(lp);
  }

  // print_A();

  return 0;
}

Submission Info

Judge Result