Lee 3D

#include <bits/stdc++.h>

using namespace std;

ifstream fin ("traseu.in");
ofstream fout ("traseu.out");

int a[105][105][105];
short N, M, niv_start, lin_start, col_start, niv_stop, lin_stop, col_stop, x, y, z;
const short dniv[] = {1, 0, 0, 0, 0, -1}, dlin[] = {0, 1, 0, 0, -1, 0}, dcol[] = {0, 0, 1, -1, 0, 0};
vector < tuple < short , short , short > > sol;

void Read () {
  fin >> N >> M;
  fin >> niv_start >> lin_start >> col_start >> niv_stop >> lin_stop >> col_stop;
  while (M --) {
    fin >> x >> y >> z;
    a[x][y][z] = -1;
  }
}

void Border () {
  for (short i = 0; i <= N + 1; i ++)
    for (short j = 0; j <= N + 1; j ++)
      a[0][i][j] = a[N + 1][i][j] = a[i][j][0] = a[i][j][N + 1] = a[i][0][j] = a[i][N + 1][j] = -1;
}

void Lee () {
  queue < tuple < short , short , short > > Q;
  Q.push (tie (niv_start , lin_start , col_start));
  a[niv_start][lin_start][col_start] = 1;
  while (a[niv_stop][lin_stop][col_stop] == 0) {
    tie(x, y, z) = Q.front();
    Q.pop();
    for (short k = 0; k < 6; k ++) {
      short xv = x + dniv[k], yv = y + dlin[k], zv = z + dcol[k];
      if (a[xv][yv][zv] == 0) {
        a[xv][yv][zv] = a[x][y][z] + 1;
        Q.push (tie (xv, yv, zv));
      }
    }
  }
}

int main () {
  Read ();
  Border ();
  Lee ();
  fout << a[niv_stop][lin_stop][col_stop] << '\n';
  sol.push_back (tie (niv_stop , lin_stop , col_stop));
  while (a[niv_stop][lin_stop][col_stop] > 1) {
    for (short k = 0; k < 6; k ++) {
      short xv = niv_stop - dniv[k], yv = lin_stop - dlin[k], zv = col_stop - dcol[k];
      if (a[xv][yv][zv] == a[niv_stop][lin_stop][col_stop] - 1) {
        niv_stop = xv, lin_stop = yv, col_stop = zv;
        break;
      }
    }
    sol.push_back (tie (niv_stop , lin_stop , col_stop));
  }
  reverse (sol.begin(), sol.end());
  for (auto it : sol) {
    tie (x, y, z) = it;
    fout << x << ' ' << y << ' ' << z << '\n';
  }
  return 0;
}