Problem p00156 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

#define rep(i, n) REP(i, 0, n)
#define REP(i, s, e) for (int i = (s); i < (int)(e); i++)
#define pb push_back
#define mp make_pair
#define all(r) r.begin(), r.end()
#define rall(r) r.rbegin(), r.rend()
#define fi first
#define se second
#define println(X) cout << X << endl;
#define DBG(X) cout << #X << " : " << X << endl;

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<ll> vl;
typedef vector<vl> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int INF = 1e9;
const ll MOD = 1e9 + 7;
double EPS = 1e-8;
const double PI = acos(-1);

// 0156

int dx[] = {-1, 1, 0, 0};
int dy[] = {0, 0, -1, 1};

int d[110][110];

bool isOutOfRange(int x, int y, int w, int h) {
  if (x < 0 || x >= w || y < 0 || y >= h)
    return true;
  return false;
}

string s[110];

int main() {
  int x, y;
  int sx, sy;
  while (cin >> x >> y && x && y) {
    rep(i, y) cin >> s[i];
    rep(i, y) rep(j, x) {
      if (s[i][j] == '&') {
        sx = j;
        sy = i;
      }
      d[i][j] = INF;
    }
    // cout<<y<<" "<<x<<endl;
    priority_queue<pair<int, pii>> q;
    q.push(mp(0, mp(sy, sx)));
    d[sy][sx] = 0;
    pair<int, pii> p;
    int ans = INF;
    while (!q.empty()) {
      p = q.top();
      q.pop();
      // cout<<" "<<p.fi<<" ("<<p.se.fi<<", "<<p.se.fi<<endl;
      rep(i, 4) {
        int nx = p.se.se + dx[i];
        int ny = p.se.fi + dy[i];
        if (isOutOfRange(nx, ny, x, y)) {
          ans = min(ans, -p.fi);
          break;
        }
        int c =
            -p.fi + ((s[p.se.fi][p.se.se] != '#' && s[ny][nx] == '#') ? 1 : 0);
        if (d[ny][nx] <= c)
          continue;
        d[ny][nx] = c;
        q.push(mp(-c, mp(ny, nx)));
      }
      if (ans != INF)
        break;
    }
    cout << ans << endl;
    // rep(i, y){
    //     rep(j, x){
    //         cout<<" "<<d[i][j];
    //     }
    //     cout<<endl;
    // }
  }
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

using namespace std;

#define rep(i, n) REP(i, 0, n)
#define REP(i, s, e) for (int i = (s); i < (int)(e); i++)
#define pb push_back
#define mp make_pair
#define all(r) r.begin(), r.end()
#define rall(r) r.rbegin(), r.rend()
#define fi first
#define se second
#define println(X) cout << X << endl;
#define DBG(X) cout << #X << " : " << X << endl;

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<ll> vl;
typedef vector<vl> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int INF = 1e9;
const ll MOD = 1e9 + 7;
double EPS = 1e-3;
const double PI = acos(-1);

int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};

double h, w;
char C[210][210];

int d[210][210];

bool isOutOfRange(int x, int y) {
  if (x <= 0 || x > w || y <= 0 || y > h)
    return true;
  return false;
}

int main() {
  pii p;
  int x, y, nx, ny, c, nc;
  int gx, gy;
  while (cin >> w >> h && h && w) {
    rep(i, h) scanf("%s", C[i]);
    // cout<<h<<" "<<w<<endl;
    rep(i, h) rep(j, w) if (C[i][j] == '&') gx = j, gy = i;
    gx++;
    gy++;
    rep(i, 210) rep(j, 210) d[i][j] = -1;
    priority_queue<pii /*, vector<pii>, greater<pii>*/> q;
    rep(i, h) q.push(mp(0, (i + 1) * 1000)),
        q.push(mp(0, (i + 1) * 1000 + w + 1));
    rep(i, w) q.push(mp(0, i + 1)), q.push(mp(0, (h + 1) * 1000 + i + 1));
    while (!q.empty()) {
      p = q.top();
      q.pop();
      y = p.se / 1000;
      x = p.se % 1000;
      c = p.fi;
      rep(i, 4) {
        nx = x + dx[i];
        ny = y + dy[i];
        if (isOutOfRange(nx, ny))
          continue;
        nc = c + (C[ny - 1][nx - 1] == '#' ? 1 : 0);
        if (d[ny][nx] != -1 && d[ny][nx] <= nc)
          continue;
        d[ny][nx] = nc;
        // if(ny==gy && nx == gx) continue;
        q.push(mp(nc, ny * 1000 + nx));
      }
    }
    cout << d[gy][gx] << endl;
  }
}