Problem p00481 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
using namespace std;
int main() {
  int Y, X, n;
  int x[10];
  int y[10];
  int ans = 0;
  cin >> Y >> X >> n;
  string a[Y];
  for (int i = 0; i < Y; i++) {
    cin >> a[i];
  }
  int step[Y + 2][X + 2];

  for (int i = 0; i < X + 2; i++) {
    step[0][i] = -2;
  }
  for (int i = 1; i <= Y; i++) {
    step[i][0] = -2;
    for (int j = 1; j <= X; j++) {
      step[i][j] = -1;
      if (a[i - 1][j - 1] == 'S') {
        x[0] = j;
        y[0] = i;
        step[i][j] = 0;
      }
      if (a[i - 1][j - 1] == '.') {
        step[i][j] = -1;
      }
      if (a[i - 1][j - 1] == 'X') {
        step[i][j] = -2;
      }
      if (a[i - 1][j - 1] == '1') {
        x[1] = j;
        y[1] = i;
      }
      if (a[i - 1][j - 1] == '2') {
        x[2] = j;
        y[2] = i;
      }
      if (a[i - 1][j - 1] == '3') {
        x[3] = j;
        y[3] = i;
      }
      if (a[i - 1][j - 1] == '4') {
        x[4] = j;
        y[4] = i;
      }
      if (a[i - 1][j - 1] == '5') {
        x[5] = j;
        y[5] = i;
      }
      if (a[i - 1][j - 1] == '6') {
        x[6] = j;
        y[6] = i;
      }
      if (a[i - 1][j - 1] == '7') {
        x[7] = j;
        y[7] = i;
      }
      if (a[i - 1][j - 1] == '8') {
        x[8] = j;
        y[8] = i;
      }
      if (a[i - 1][j - 1] == '9') {
        x[9] = j;
        y[9] = i;
      }
    }
    step[i][X + 1] = -2;
  }
  for (int i = 0; i < X + 2; i++) {
    step[Y + 1][i] = -2;
  }

  queue<pair<int, int>> q;

  q.push(make_pair(y[0], x[0]));

  for (int i = 0; i < n; i++) {
    while (q.empty() == false) {
      if (q.front().first == y[i + 1] && q.front().second == x[i + 1]) {
        ans += step[y[i + 1]][x[i + 1]];
        for (int j = 1; j <= Y; j++) {
          for (int k = 1; k <= X; k++) {
            if (step[j][k] != -2)
              step[j][k] = -1;
          }
        }
        step[y[i + 1]][x[i + 1]] = 0;
        while (!q.empty()) {
          q.pop();
        }
        q.push(make_pair(y[i + 1], x[i + 1]));
        break;
      }
      if (step[q.front().first + 1][q.front().second] == -1) {
        step[q.front().first + 1][q.front().second] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first + 1, q.front().second));
      }
      if (step[q.front().first - 1][q.front().second] == -1) {
        step[q.front().first - 1][q.front().second] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first - 1, q.front().second));
      }
      if (step[q.front().first][q.front().second + 1] == -1) {
        step[q.front().first][q.front().second + 1] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first, q.front().second + 1));
      }
      if (step[q.front().first][q.front().second - 1] == -1) {
        step[q.front().first][q.front().second - 1] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first, q.front().second - 1));
      }
      // for(int j = 1; j <= Y; j++) {
      //     for(int k = 1; k <= X; k++) {
      //         if(step[j][k] > -1)
      //             cout << " ";
      //         cout << step[j][k] << " ";
      //     }
      //     cout << endl;
      // }
      // cout << endl;
      q.pop();
    }
  }
  cout << ans << endl;
  return 0;
}


Error: 0

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
int main() {
  int Y, X, n;
  int x[10];
  int y[10];
  int ans = 0;
  cin >> Y >> X >> n;
  string a[Y];
  for (int i = 0; i < Y; i++) {
    cin >> a[i];
  }
  int step[Y + 2][X + 2];

  for (int i = 0; i < X + 2; i++) {
    step[0][i] = -2;
  }
  for (int i = 1; i <= Y; i++) {
    step[i][0] = -2;
    for (int j = 1; j <= X; j++) {
      if (a[i - 1][j - 1] == 'S') {
        x[0] = j;
        y[0] = i;
        step[i][j] = 0;
      }
      if (a[i - 1][j - 1] == '.') {
        step[i][j] = -1;
      }
      if (a[i - 1][j - 1] == 'X') {
        step[i][j] = -2;
      }
      if (a[i - 1][j - 1] == '1') {
        x[1] = j;
        y[1] = i;
        step[i][j] = 1;
      }
      if (a[i - 1][j - 1] == '2') {
        x[2] = j;
        y[2] = i;
        step[i][j] = 2;
      }
      if (a[i - 1][j - 1] == '3') {
        x[3] = j;
        y[3] = i;
        step[i][j] = 3;
      }
      if (a[i - 1][j - 1] == '4') {
        x[4] = j;
        y[4] = i;
        step[i][j] = 4;
      }
      if (a[i - 1][j - 1] == '5') {
        x[5] = j;
        y[5] = i;
        step[i][j] = 5;
      }
      if (a[i - 1][j - 1] == '6') {
        x[6] = j;
        y[6] = i;
        step[i][j] = 6;
      }
      if (a[i - 1][j - 1] == '7') {
        x[7] = j;
        y[7] = i;
        step[i][j] = 7;
      }
      if (a[i - 1][j - 1] == '8') {
        x[8] = j;
        y[8] = i;
        step[i][j] = 8;
      }
      if (a[i - 1][j - 1] == '9') {
        x[9] = j;
        y[9] = i;
        step[i][j] = 9;
      }
    }
    step[i][X + 1] = -2;
  }
  for (int i = 0; i < X + 2; i++) {
    step[Y + 1][i] = -2;
  }

  queue<pair<int, int>> q;

  q.push(make_pair(y[0], x[0]));

  for (int i = 0; i < n; i++) {
    while (q.empty() == false) {
      if (q.front().first == y[i + 1] && q.front().second == x[i + 1]) {
        ans += step[y[i + 1]][x[i + 1]];
        for (int j = 1; j <= Y; j++) {
          for (int k = 1; k <= X; k++) {
            step[j][k] = -1;
          }
        }
        break;
      }
      if (step[q.front().first + 1][q.front().second] != -2) {
        step[q.front().first + 1][q.front().second] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first + 1, q.front().second));
      }
      if (step[q.front().first - 1][q.front().second] != -2) {
        step[q.front().first - 1][q.front().second] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first - 1, q.front().second));
      }
      if (step[q.front().first][q.front().second + 1] != -2) {
        step[q.front().first][q.front().second + 1] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first, q.front().second + 1));
      }
      if (step[q.front().first][q.front().second - 1] != -2) {
        step[q.front().first][q.front().second - 1] =
            step[q.front().first][q.front().second] + 1;
        q.push(make_pair(q.front().first, q.front().second - 1));
      }
      q.pop();
    }
  }
  cout << ans << endl;
  return 0;
}