Problem p01561 (C++) — buggy submission, verdict: Memory Limit Exceeded

#include <bits/stdc++.h>

#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)

#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)

#define _all(arg) begin(arg), end(arg)
#define uniq(arg) sort(_all(arg)), (arg).erase(unique(_all(arg)), end(arg))
#define getidx(ary, key) lower_bound(_all(ary), key) - begin(ary)
#define clr(a, b) memset((a), (b), sizeof(a))
#define bit(n) (1LL << (n))

// #define DEBUG

#ifdef DEBUG
#define dump(...) fprintf(stderr, __VA_ARGS__)
#else
#define dump(...)
#endif

template <class T> bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}

using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;

const double EPS = 1e-10;
const double PI = acos(-1.0);
const int inf = 1 << 30;
const ll mod = 1000000007LL;
const short dx[4] = {1, 0, -1, 0};
const short dy[4] = {0, 1, 0, -1};

ll extgcd(ll a, ll b, ll &x, ll &y) {
  x = 1, y = 0;
  ll g = a;
  if (b != 0)
    g = extgcd(b, a % b, y, x), y -= a / b * x;
  return g;
}
ll ADD(const ll &a, const ll &b, const ll &mod) { return (a + b) % mod; }
ll SUB(const ll &a, const ll &b, const ll &mod) { return (a - b + mod) % mod; }
ll MUL(const ll &a, const ll &b, const ll &mod) { return (1LL * a * b) % mod; }
ll DIV(const ll &a, const ll &b, const ll &mod) {
  ll x, y;
  extgcd(b, mod, x, y);
  return MUL(a, (x + mod) % mod, mod);
}

random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> dice(1, 6);
uniform_real_distribution<double> score(0.0, 10.0);

using vs = vector<string>;
using vvi = vector<vi>;
using vb = vector<bool>;
using vvb = vector<vb>;
using State = tuple<short, short, int, char>;

int min_cost[50][50][1024][2];

int main(void) {
  int w, h;
  cin >> w >> h;

  vs field(h);
  vvi sw_idx(h, vi(w, -1));
  int sx, sy, tx, ty;
  rep(y, h) {
    cin >> field[y];
    rep(x, w) {
      if (field[y][x] == '%') {
        sx = x, sy = y;
        field[y][x] = '_';
      }
      if (field[y][x] == '&') {
        tx = x, ty = y;
        field[y][x] = '_';
      }
      if (isupper(field[y][x])) {
        sw_idx[y][x] = field[y][x] - 'A';
        field[y][x] = '^';
      }
      if (islower(field[y][x])) {
        sw_idx[y][x] = field[y][x] - 'a';
        field[y][x] = '_';
      }
    }
  }

  int n;
  cin >> n;
  vvi sw_field(h, vi(w));

  rep(i, n) {
    rep(y, h) {
      rep(x, w) {
        char c;
        cin >> c;
        if (c == '*')
          sw_field[y][x] |= (1 << i);
      }
    }
  }

  queue<State> q;
  q.push(State(sx, sy, 0, '_'));

  // vector<vector<vvi>> min_cost(h, vector<vvi>(w, vvi(1 << n, vi(2, inf))));
  rep(i, h) rep(j, w) rep(k, 1 << n) rep(l, 2) min_cost[i][j][k][l] = inf;
  min_cost[sy][sx][0][0] = 0;

  while (q.size()) {
    short cx, cy;
    int cb;
    char cf;
    tie(cx, cy, cb, cf) = q.front();
    q.pop();

    int cfi = (cf == '^');

    if (cx == tx and cy == ty) {
      cout << min_cost[cy][cx][cb][cfi] << endl;
      return 0;
    }

    int nc = min_cost[cy][cx][cb][cfi] + 1;

    if (field[cy][cx] == '|') {
      char nf = (cf == '^' ? '_' : '^');
      int nfi = (nf == '^');

      if (chmin(min_cost[cy][cx][cb][nfi], nc)) {
        q.push(State(cx, cy, cb, nf));
      }
    }

    if (sw_idx[cy][cx] != -1) {
      int idx = sw_idx[cy][cx];

      int nb = cb ^ (1 << idx);
      char nf = cf;
      if (sw_field[cy][cx] & (1 << idx)) {
        nf = (cf == '^' ? '_' : '^');
      }
      int nfi = (nf == '^');
      if (chmin(min_cost[cy][cx][nb][nfi], nc)) {
        q.push(State(cx, cy, nb, nf));
      }
    }

    rep(i, 4) {
      short nx = cx + dx[i], ny = cy + dy[i];

      if (field[ny][nx] == '#')
        continue;

      if (field[ny][nx] == '|' and chmin(min_cost[ny][nx][cb][cfi], nc)) {
        q.push(State(nx, ny, cb, cf));
        continue;
      }

      bool nrev = (__builtin_popcount(sw_field[ny][nx] & cb) % 2 == 1);

      char nf;
      if (nrev)
        nf = (field[ny][nx] == '^' ? '_' : '^');
      else
        nf = field[ny][nx];
      int nfi = (nf == '^');

      if (cf == nf and chmin(min_cost[ny][nx][cb][nfi], nc)) {
        q.push(State(nx, ny, cb, nf));
      }
    }
  }

  cout << -1 << endl;

  return 0;
}

Error: MLE

Fixed submission:

#include <bits/stdc++.h>

#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)

#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)

#define _all(arg) begin(arg), end(arg)
#define uniq(arg) sort(_all(arg)), (arg).erase(unique(_all(arg)), end(arg))
#define getidx(ary, key) lower_bound(_all(ary), key) - begin(ary)
#define clr(a, b) memset((a), (b), sizeof(a))
#define bit(n) (1LL << (n))

// #define DEBUG

#ifdef DEBUG
#define dump(...) fprintf(stderr, __VA_ARGS__)
#else
#define dump(...)
#endif

template <class T> bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}

using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;

const double EPS = 1e-10;
const double PI = acos(-1.0);
const int inf = 1 << 30;
const ll mod = 1000000007LL;
const short dx[4] = {1, 0, -1, 0};
const short dy[4] = {0, 1, 0, -1};

ll extgcd(ll a, ll b, ll &x, ll &y) {
  x = 1, y = 0;
  ll g = a;
  if (b != 0)
    g = extgcd(b, a % b, y, x), y -= a / b * x;
  return g;
}
ll ADD(const ll &a, const ll &b, const ll &mod) { return (a + b) % mod; }
ll SUB(const ll &a, const ll &b, const ll &mod) { return (a - b + mod) % mod; }
ll MUL(const ll &a, const ll &b, const ll &mod) { return (1LL * a * b) % mod; }
ll DIV(const ll &a, const ll &b, const ll &mod) {
  ll x, y;
  extgcd(b, mod, x, y);
  return MUL(a, (x + mod) % mod, mod);
}

random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> dice(1, 6);
uniform_real_distribution<double> score(0.0, 10.0);

using vs = vector<string>;
using vvi = vector<vi>;
using vb = vector<bool>;
using vvb = vector<vb>;
using State = tuple<short, short, int, char>;

int main(void) {
  int w, h;
  cin >> w >> h;

  vs field(h);
  vvi sw_idx(h, vi(w, -1));
  int sx, sy, tx, ty;
  rep(y, h) {
    cin >> field[y];
    rep(x, w) {
      if (field[y][x] == '%') {
        sx = x, sy = y;
        field[y][x] = '_';
      }
      if (field[y][x] == '&') {
        tx = x, ty = y;
        field[y][x] = '_';
      }
      if (isupper(field[y][x])) {
        sw_idx[y][x] = field[y][x] - 'A';
        field[y][x] = '^';
      }
      if (islower(field[y][x])) {
        sw_idx[y][x] = field[y][x] - 'a';
        field[y][x] = '_';
      }
    }
  }

  int n;
  cin >> n;
  vvi sw_field(h, vi(w));

  rep(i, n) {
    rep(y, h) {
      rep(x, w) {
        char c;
        cin >> c;
        if (c == '*')
          sw_field[y][x] |= (1 << i);
      }
    }
  }

  queue<State> q;
  q.push(State(sx, sy, 0, '_'));

  vector<vector<vvi>> min_cost(h, vector<vvi>(w, vvi(1 << n, vi(2, inf))));
  min_cost[sy][sx][0][0] = 0;

  while (q.size()) {
    short cx, cy;
    int cb;
    char cf;
    tie(cx, cy, cb, cf) = q.front();
    q.pop();

    int cfi = (cf == '^');

    if (cx == tx and cy == ty) {
      cout << min_cost[cy][cx][cb][cfi] << endl;
      return 0;
    }

    int nc = min_cost[cy][cx][cb][cfi] + 1;

    if (field[cy][cx] == '|') {
      char nf = (cf == '^' ? '_' : '^');
      int nfi = (nf == '^');

      if (chmin(min_cost[cy][cx][cb][nfi], nc)) {
        q.push(State(cx, cy, cb, nf));
      }
    }

    if (sw_idx[cy][cx] != -1) {
      int idx = sw_idx[cy][cx];

      int nb = cb ^ (1 << idx);
      char nf = cf;
      if (sw_field[cy][cx] & (1 << idx)) {
        nf = (cf == '^' ? '_' : '^');
      }
      int nfi = (nf == '^');
      if (chmin(min_cost[cy][cx][nb][nfi], nc)) {
        q.push(State(cx, cy, nb, nf));
      }
    }

    rep(i, 4) {
      short nx = cx + dx[i], ny = cy + dy[i];

      if (field[ny][nx] == '#')
        continue;

      if (field[ny][nx] == '|' and chmin(min_cost[ny][nx][cb][cfi], nc)) {
        q.push(State(nx, ny, cb, cf));
        continue;
      }

      bool nrev = (__builtin_popcount(sw_field[ny][nx] & cb) % 2 == 1);

      char nf;
      if (nrev)
        nf = (field[ny][nx] == '^' ? '_' : '^');
      else
        nf = field[ny][nx];
      int nfi = (nf == '^');

      if (cf == nf and chmin(min_cost[ny][nx][cb][nfi], nc)) {
        q.push(State(nx, ny, cb, nf));
      }
    }
  }

  cout << -1 << endl;

  return 0;
}