Problem p01755 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <string>
#include <vector>
//    #include <boost/multiprecision/cpp_int.hpp>
#include <functional>
#define int long long
#define inf 1000000007
#define pa pair<int, int>
#define ll long long
#define pal pair<double, pa>
#define ppap pair<pa, int>

#define ssa pair<string, int>
#define mp make_pair
#define pb push_back
#define EPS (1e-10)
#define equals(a, b) (fabs((a) - (b)) < EPS)

using namespace std;
class pas {
public:
  int x, y, h;
  pas(int x = 0, int y = 0, int h = 0) : x(x), y(y), h(h) {}
  bool operator<(const pas &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pas &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};
class pa2 {
public:
  int x, y;
  pa2(int x = 0, int y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  bool operator<(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};

#define ppa pair<int, pas>
class Point {
public:
  double x, y;
  Point(double x = 0, double y = 0) : x(x), y(y) {}
  Point operator+(Point p) { return Point(x + p.x, y + p.y); }
  Point operator-(Point p) { return Point(x - p.x, y - p.y); }
  Point operator*(double a) { return Point(x * a, y * a); }
  Point operator/(double a) { return Point(x / a, y / a); }
  double absv() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  bool operator<(const Point &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const Point &p) const {
    return fabs(x - p.x) < EPS && fabs(y - p.y) < EPS;
  }
};
typedef Point Vector;
#define pl pair<int, pas>
struct Segment {
  Point p1, p2;
};
double dot(Vector a, Vector b) { return a.x * b.x + a.y * b.y; }
double cross(Vector a, Vector b) { return a.x * b.y - a.y * b.x; }

bool parareru(Point a, Point b, Point c, Point d) {
  //	if(abs(cross(a-b,d-c))<EPS)cout<<"dd "<<cross(a-b,d-c)<<endl;
  return abs(cross(a - b, d - c)) < EPS;
}
double distance_ls_p(Point a, Point b, Point c) {
  if (dot(b - a, c - a) < EPS)
    return (c - a).absv();
  if (dot(a - b, c - b) < EPS)
    return (c - b).absv();
  return abs(cross(b - a, c - a)) / (b - a).absv();
}
bool is_intersected_ls(Segment a, Segment b) {
  if (a.p1 == b.p1 || a.p2 == b.p1 || a.p1 == b.p2 || a.p2 == b.p2)
    return false;
  if (parareru((a.p2), (a.p1), (a.p1), (b.p2)) &&
      parareru((a.p2), (a.p1), (a.p1), (b.p1))) {
    //		cout<<"sss"<<endl;
    if (dot(a.p1 - b.p1, a.p1 - b.p2) < EPS)
      return true;
    if (dot(a.p2 - b.p1, a.p2 - b.p2) < EPS)
      return true;
    if (dot(a.p1 - b.p1, a.p2 - b.p1) < EPS)
      return true;
    if (dot(a.p1 - b.p2, a.p2 - b.p2) < EPS)
      return true;
    return false;
  } else
    return (cross(a.p2 - a.p1, b.p1 - a.p1) * cross(a.p2 - a.p1, b.p2 - a.p1) <
            EPS) &&
           (cross(b.p2 - b.p1, a.p1 - b.p1) * cross(b.p2 - b.p1, a.p2 - b.p1) <
            EPS);
}

double segment_dis(Segment a, Segment b) {
  if (is_intersected_ls(a, b))
    return 0;
  double r = distance_ls_p(a.p1, a.p2, b.p1);
  r = min(r, distance_ls_p(a.p1, a.p2, b.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p1));
  return r;
}
Point intersection_ls(Segment a, Segment b) {
  Point ba = b.p2 - b.p1;
  double d1 = abs(cross(ba, a.p1 - b.p1));
  double d2 = abs(cross(ba, a.p2 - b.p1));
  double t = d1 / (d1 + d2);

  return a.p1 + (a.p2 - a.p1) * t;
}

string itos(int i) {
  ostringstream s;
  s << i;
  return s.str();
}

int gcd(int v, int b) {
  if (v > b)
    return gcd(b, v);
  if (v == b)
    return b;
  if (b % v == 0)
    return v;
  return gcd(v, b % v);
}

double distans(double x1, double y1, double x2, double y2) {
  double rr = (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
  return sqrt(rr);
}

//         int pr[2000010];
//       int inv[2000010];
/*
int beki(int wa,int rr,int warukazu){
    if(rr==0) return 1ll;
    if(rr==1) return wa%warukazu;
    if(rr%2==1) return (beki(wa,rr-1,warukazu)*wa)%warukazu;
    int zx=beki(wa,rr/2,warukazu);
    return (zx*zx)%warukazu;
}

            int comb(int nn,int rr){
                    int r=pr[nn]*inv[rr];
                    r%=inf;
                    r*=inv[nn-rr];
                    r%=inf;
                    return r;
            }

void gya(int ert){
    pr[0]=1;
    for(int i=1;i<ert;i++){
            pr[i]=(pr[i-1]*i)%inf;
    }
    for(int i=0;i<ert;i++) inv[i]=beki(pr[i],inf-2,inf);

}
 */

// sort(ve.begin(),ve.end(),greater<int>());
//----------------kokomade tenpure------------
// vector<double> ans(100000000),ans2(100000000);

int h, w;
int a[51][51] = {0};
int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, 1, 0, -1};
int x, y;
int muki = 0;
int sx, sy, gx, gy;
string s;
int it = 0;
int cnt = 0;
void bun();
void dousa() {
  cnt++;

  if (cnt > 5000000) {
    cout << -1 << endl;
    exit(0);
  }
  if (s[it] == '^') {
    x += dx[muki];
    y += dy[muki];
    if (a[x][y]) {
      x -= dx[muki];
      y -= dy[muki];
    }

  } else if (s[it] == 'v') {
    x -= dx[muki];
    y -= dy[muki];
    if (a[x][y]) {
      x += dx[muki];
      y += dy[muki];
    }
  } else if (s[it] == '<') {
    muki += 3;
    muki %= 4;
  } else if (s[it] == '>') {
    muki++;
    muki %= 4;
  }
  if (x == gx && y == gy) {
    cout << cnt << endl;
    exit(0);
  }
  it++;
}

void ifu() {
  it++;
  bool han = 0;
  if (s[it] == '~') {
    han = 1;
    it++;
  }
  bool b;
  if (s[it] == 'N') {
    if (muki == 0)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'E') {
    if (muki == 1)
      b = 1;
    else
      b = 0;

  } else if (s[it] == 'W') {
    if (muki == 3)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'S') {
    if (muki == 2)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'C') {
    if (a[x + dx[muki]][y + dy[muki]])
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'T') {
    b = 1;
  }
  b ^= han;
  it++;
  if (b) {
    while (s[it] != ']')
      bun();
    it++;
  } else {
    int r = 0;
    while (1) {
      if (r == 0 && s[it] == ']')
        break;

      if (s[it] == '{' || s[it] == '[')
        r++;
      else if (s[it] == '}' || s[it] == ']')
        r--;
      it++;
    }

    it++;
  }
}

void whi() {
  it++;
  int we = it;
lll:;
  it = we;
  bool han = 0;
  if (s[it] == '~') {
    han = 1;
    it++;
  }

  int ddx = x, ddy = y, mmk = muki;
  bool b;
  if (s[it] == 'N') {
    if (muki == 0)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'E') {
    if (muki == 1)
      b = 1;
    else
      b = 0;

  } else if (s[it] == 'W') {
    if (muki == 3)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'S') {
    if (muki == 2)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'C') {
    if (a[x + dx[muki]][y + dy[muki]])
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'T') {
    b = 1;
  }
  b ^= han;
  it++;
  if (b) {
    if (s[it] == '}') {
      cout << -1 << endl;
      exit(0);
    }
    while (s[it] != '}')
      bun();
    it++;
    if (x == ddx && y == ddy && mmk == muki) {
      cout << -1 << endl;
      exit(0);
    }
    goto lll;
  } else {
    int r = 0;
    while (1) {
      if (r == 0 && s[it] == '}')
        break;

      if (s[it] == '{' || s[it] == '[')
        r++;
      else if (s[it] == '}' || s[it] == ']')
        r--;
      it++;
    }

    it++;
  }
}

void bun() {
  if (s[it] == '[')
    ifu();
  else if (s[it] == '{')
    whi();
  else
    dousa();
}

void saisho() {
  while (s[it] != '&')
    bun();
  cout << "-1" << endl;
  exit(0);
}

signed main() {
  cin >> h >> w;

  for (int i = 0; i < h; i++) {
    string st;
    cin >> st;

    for (int j = 0; j < w; j++) {
      if (st[j] == '#')
        a[i][j] = 1;
      if (st[j] == 's')
        sx = i, sy = j;
      if (st[j] == 'g')
        gx = i, gy = j;
    }
  }
  cin >> s;
  s += "&";
  x = sx, y = sy;
  saisho();
  return 0;
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <string>
#include <vector>
//    #include <boost/multiprecision/cpp_int.hpp>
#include <functional>
#define int long long
#define inf 1000000007
#define pa pair<int, int>
#define ll long long
#define pal pair<double, pa>
#define ppap pair<pa, int>

#define ssa pair<string, int>
#define mp make_pair
#define pb push_back
#define EPS (1e-10)
#define equals(a, b) (fabs((a) - (b)) < EPS)

using namespace std;
class pas {
public:
  int x, y, h;
  pas(int x = 0, int y = 0, int h = 0) : x(x), y(y), h(h) {}
  bool operator<(const pas &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pas &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};
class pa2 {
public:
  int x, y;
  pa2(int x = 0, int y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  bool operator<(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};

#define ppa pair<int, pas>
class Point {
public:
  double x, y;
  Point(double x = 0, double y = 0) : x(x), y(y) {}
  Point operator+(Point p) { return Point(x + p.x, y + p.y); }
  Point operator-(Point p) { return Point(x - p.x, y - p.y); }
  Point operator*(double a) { return Point(x * a, y * a); }
  Point operator/(double a) { return Point(x / a, y / a); }
  double absv() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  bool operator<(const Point &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const Point &p) const {
    return fabs(x - p.x) < EPS && fabs(y - p.y) < EPS;
  }
};
typedef Point Vector;
#define pl pair<int, pas>
struct Segment {
  Point p1, p2;
};
double dot(Vector a, Vector b) { return a.x * b.x + a.y * b.y; }
double cross(Vector a, Vector b) { return a.x * b.y - a.y * b.x; }

bool parareru(Point a, Point b, Point c, Point d) {
  //	if(abs(cross(a-b,d-c))<EPS)cout<<"dd "<<cross(a-b,d-c)<<endl;
  return abs(cross(a - b, d - c)) < EPS;
}
double distance_ls_p(Point a, Point b, Point c) {
  if (dot(b - a, c - a) < EPS)
    return (c - a).absv();
  if (dot(a - b, c - b) < EPS)
    return (c - b).absv();
  return abs(cross(b - a, c - a)) / (b - a).absv();
}
bool is_intersected_ls(Segment a, Segment b) {
  if (a.p1 == b.p1 || a.p2 == b.p1 || a.p1 == b.p2 || a.p2 == b.p2)
    return false;
  if (parareru((a.p2), (a.p1), (a.p1), (b.p2)) &&
      parareru((a.p2), (a.p1), (a.p1), (b.p1))) {
    //		cout<<"sss"<<endl;
    if (dot(a.p1 - b.p1, a.p1 - b.p2) < EPS)
      return true;
    if (dot(a.p2 - b.p1, a.p2 - b.p2) < EPS)
      return true;
    if (dot(a.p1 - b.p1, a.p2 - b.p1) < EPS)
      return true;
    if (dot(a.p1 - b.p2, a.p2 - b.p2) < EPS)
      return true;
    return false;
  } else
    return (cross(a.p2 - a.p1, b.p1 - a.p1) * cross(a.p2 - a.p1, b.p2 - a.p1) <
            EPS) &&
           (cross(b.p2 - b.p1, a.p1 - b.p1) * cross(b.p2 - b.p1, a.p2 - b.p1) <
            EPS);
}

double segment_dis(Segment a, Segment b) {
  if (is_intersected_ls(a, b))
    return 0;
  double r = distance_ls_p(a.p1, a.p2, b.p1);
  r = min(r, distance_ls_p(a.p1, a.p2, b.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p1));
  return r;
}
Point intersection_ls(Segment a, Segment b) {
  Point ba = b.p2 - b.p1;
  double d1 = abs(cross(ba, a.p1 - b.p1));
  double d2 = abs(cross(ba, a.p2 - b.p1));
  double t = d1 / (d1 + d2);

  return a.p1 + (a.p2 - a.p1) * t;
}

string itos(int i) {
  ostringstream s;
  s << i;
  return s.str();
}

int gcd(int v, int b) {
  if (v > b)
    return gcd(b, v);
  if (v == b)
    return b;
  if (b % v == 0)
    return v;
  return gcd(v, b % v);
}

double distans(double x1, double y1, double x2, double y2) {
  double rr = (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
  return sqrt(rr);
}

//         int pr[2000010];
//       int inv[2000010];
/*
int beki(int wa,int rr,int warukazu){
    if(rr==0) return 1ll;
    if(rr==1) return wa%warukazu;
    if(rr%2==1) return (beki(wa,rr-1,warukazu)*wa)%warukazu;
    int zx=beki(wa,rr/2,warukazu);
    return (zx*zx)%warukazu;
}

            int comb(int nn,int rr){
                    int r=pr[nn]*inv[rr];
                    r%=inf;
                    r*=inv[nn-rr];
                    r%=inf;
                    return r;
            }

void gya(int ert){
    pr[0]=1;
    for(int i=1;i<ert;i++){
            pr[i]=(pr[i-1]*i)%inf;
    }
    for(int i=0;i<ert;i++) inv[i]=beki(pr[i],inf-2,inf);

}
 */

// sort(ve.begin(),ve.end(),greater<int>());
//----------------kokomade tenpure------------
// vector<double> ans(100000000),ans2(100000000);

int h, w;
int a[51][51] = {0};
int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, 1, 0, -1};
int x, y;
int muki = 0;
int sx, sy, gx, gy;
string s;
int it = 0;
int cnt = 0;
void bun();
void dousa() {
  cnt++;

  if (cnt > 1000000) {
    cout << -1 << endl;
    exit(0);
  }
  if (s[it] == '^') {
    x += dx[muki];
    y += dy[muki];
    if (a[x][y]) {
      x -= dx[muki];
      y -= dy[muki];
    }

  } else if (s[it] == 'v') {
    x -= dx[muki];
    y -= dy[muki];
    if (a[x][y]) {
      x += dx[muki];
      y += dy[muki];
    }
  } else if (s[it] == '<') {
    muki += 3;
    muki %= 4;
  } else if (s[it] == '>') {
    muki++;
    muki %= 4;
  }
  if (x == gx && y == gy) {
    cout << cnt << endl;
    exit(0);
  }
  it++;
}

void ifu() {
  it++;
  bool han = 0;
  if (s[it] == '~') {
    han = 1;
    it++;
  }
  bool b;
  if (s[it] == 'N') {
    if (muki == 0)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'E') {
    if (muki == 1)
      b = 1;
    else
      b = 0;

  } else if (s[it] == 'W') {
    if (muki == 3)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'S') {
    if (muki == 2)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'C') {
    if (a[x + dx[muki]][y + dy[muki]])
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'T') {
    b = 1;
  }
  b ^= han;
  it++;
  if (b) {
    while (s[it] != ']')
      bun();
    it++;
  } else {
    int r = 0;
    while (1) {
      if (r == 0 && s[it] == ']')
        break;

      if (s[it] == '{' || s[it] == '[')
        r++;
      else if (s[it] == '}' || s[it] == ']')
        r--;
      it++;
    }

    it++;
  }
}

void whi() {
  it++;
  int we = it;
lll:;
  it = we;
  bool han = 0;
  if (s[it] == '~') {
    han = 1;
    it++;
  }
  bool b;
  if (s[it] == 'N') {
    if (muki == 0)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'E') {
    if (muki == 1)
      b = 1;
    else
      b = 0;

  } else if (s[it] == 'W') {
    if (muki == 3)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'S') {
    if (muki == 2)
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'C') {
    if (a[x + dx[muki]][y + dy[muki]])
      b = 1;
    else
      b = 0;
  } else if (s[it] == 'T') {
    b = 1;
  }
  b ^= han;
  it++;
  if (b) {
    if (s[it] == '}') {
      cout << -1 << endl;
      exit(0);
    }
    while (s[it] != '}')
      bun();
    it++;
    goto lll;
  } else {
    int r = 0;
    while (1) {
      if (r == 0 && s[it] == '}')
        break;

      if (s[it] == '{' || s[it] == '[')
        r++;
      else if (s[it] == '}' || s[it] == ']')
        r--;
      it++;
    }

    it++;
  }
}

void bun() {
  if (s[it] == '[')
    ifu();
  else if (s[it] == '{')
    whi();
  else
    dousa();
}

void saisho() {
  while (s[it] != '&')
    bun();
  cout << "-1" << endl;
  exit(0);
}

signed main() {
  cin >> h >> w;

  for (int i = 0; i < h; i++) {
    string st;
    cin >> st;

    for (int j = 0; j < w; j++) {
      if (st[j] == '#')
        a[i][j] = 1;
      if (st[j] == 's')
        sx = i, sy = j;
      if (st[j] == 'g')
        gx = i, gy = j;
    }
  }
  cin >> s;
  s += "&";
  x = sx, y = sy;
  saisho();
  return 0;
}