Problem p02631 (C++) — buggy submission, verdict: Runtime Error

/*                        _
                       _oo0oo_
                      o8888888o
                      88" . "88
                      (| -_- |)
                      0\\  =  /0
                   ____/`---'\\____
                  /  \\\\|     |//  \\
                 / \\\\||| /:\\ |||// \\
                / _||||| -:- |||||- \\
               |   | \\\\\\ \\-/ /// |   |
               | \\_|  ''\\---/''  |_/ |
               \\  .-\\__  '-'  ___/-. /
            ____'. .'  /--.--\\  `. .'_____
          /"" '<  `.___\\_<|>_/___.' >' "" \\
         | | :  `- \\`.;`\\ _ /`;.`/ - ` : | |
         \\  \\ `_.   \\_ __\\ /__ _/   .-` / _/
          `-.____`.___ \\_____/___.-`___.-'

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 JENISH MONPARA S.    IIT PATNA    I_LOVE_ADITI_GOEL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define LIM 100005

#define fio                                                                    \\
  ios_base::sync_with_stdio(0);                                                \\
  cin.tie(0);                                                                  \\
  cout.tie(0)
#define mpq priority_queue<int, vector<int>, greater<int>>
#define deb(a) cerr << #a << ": " << a << endl
#define ftt                                                                    \\
  cin >> t;                                                                    \\
  for (int tt = 1; tt <= t; ++tt)
#define forr(i, n) for ((i) = 1; (i) <= (n); (i)++)
#define Rev(v) reverse(v.begin(), v.end())
#define Sort(v) sort(v.begin(), v.end())
#define mem(a, b) memset(a, b, sizeof(a))
#define umii unordered_map<int, int>
#define all(a) a.begin(), a.end()
#define vvi vector<vector<int>>
#define pq priority_queue<int>
#define sqr(a) (((a) * (a)))
#define double long double
#define dbg cout << "\\nhi\\n"
#define pii pair<int, int>
#define mii map<int, int>
#define vb vector<bool>
#define eb emplace_back
#define vi vector<int>
#define nl cout << "\\n"
#define pb push_back
#define int long long
#define sp << " " <<
#define se second
#define fi first

int fpow(int x, int y, int m) {
  int temp;
  if (y == 0 || x == 1)
    return 1;
  temp = fpow(x, y / 2, m);
  if (y % 2 == 0)
    return ((temp) * (temp)) % m;
  else
    return (((x) % m) * ((temp * temp) % m)) % m;
}
int gcd(int a, int b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
void sieve(int n) {
  bool prime[5 * LIM];
  memset(prime, true, sizeof(prime));
  int rootn = (int)sqrt(n);
  for (int p = 2; p <= rootn; p++)
    if (prime[p] == true)
      for (int i = p * p; i <= n; i += p)
        prime[i] = false;
  prime[1] = 0;
}

int cnt, sum, mid, mx = -1e17, mn = 1e17;
int n, m, d, t, i, j, k, l, r, x, y, z;
bool f, f1, f2;
string s;
vi a(2 * LIM);
//*************************************************************************************************************************

int32_t main() {
  fio;
  cin >> n;
  forr(i, n) cin >> a[i];
  vi pre(2 * LIM, 0), suff(2 * LIM, 0);
  x = 0;
  forr(i, n) {
    pre[i] = x;
    x ^= a[i];
  }
  x = 0;
  for (i = n; i > 0; i--) {
    suff[i] = x;
    x ^= a[i];
  }
  forr(i, n) { cout << (pre[i] ^ suff[i]) << " "; }
}


Error: WA

Fixed submission:

/*                        _
                       _oo0oo_
                      o8888888o
                      88" . "88
                      (| -_- |)
                      0\\  =  /0
                   ____/`---'\\____
                  /  \\\\|     |//  \\
                 / \\\\||| /:\\ |||// \\
                / _||||| -:- |||||- \\
               |   | \\\\\\ \\-/ /// |   |
               | \\_|  ''\\---/''  |_/ |
               \\  .-\\__  '-'  ___/-. /
            ____'. .'  /--.--\\  `. .'_____
          /"" '<  `.___\\_<|>_/___.' >' "" \\
         | | :  `- \\`.;`\\ _ /`;.`/ - ` : | |
         \\  \\ `_.   \\_ __\\ /__ _/   .-` / _/
          `-.____`.___ \\_____/___.-`___.-'

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 JENISH MONPARA S.    IIT PATNA    I_LOVE_ADITI_GOEL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define LIM 100005

#define fio                                                                    \\
  ios_base::sync_with_stdio(0);                                                \\
  cin.tie(0);                                                                  \\
  cout.tie(0)
#define mpq priority_queue<int, vector<int>, greater<int>>
#define deb(a) cerr << #a << ": " << a << endl
#define ftt                                                                    \\
  cin >> t;                                                                    \\
  for (int tt = 1; tt <= t; ++tt)
#define forr(i, n) for ((i) = 1; (i) <= (n); (i)++)
#define Rev(v) reverse(v.begin(), v.end())
#define Sort(v) sort(v.begin(), v.end())
#define mem(a, b) memset(a, b, sizeof(a))
#define umii unordered_map<int, int>
#define all(a) a.begin(), a.end()
#define vvi vector<vector<int>>
#define pq priority_queue<int>
#define sqr(a) (((a) * (a)))
#define double long double
#define dbg cout << "\\nhi\\n"
#define pii pair<int, int>
#define mii map<int, int>
#define vb vector<bool>
#define eb emplace_back
#define vi vector<int>
#define nl cout << "\\n"
#define pb push_back
#define int long long
#define sp << " " <<
#define se second
#define fi first

int fpow(int x, int y, int m) {
  int temp;
  if (y == 0 || x == 1)
    return 1;
  temp = fpow(x, y / 2, m);
  if (y % 2 == 0)
    return ((temp) * (temp)) % m;
  else
    return (((x) % m) * ((temp * temp) % m)) % m;
}
int gcd(int a, int b) {
  if (b == 0)
    return a;
  return gcd(b, a % b);
}
void sieve(int n) {
  bool prime[5 * LIM];
  memset(prime, true, sizeof(prime));
  int rootn = (int)sqrt(n);
  for (int p = 2; p <= rootn; p++)
    if (prime[p] == true)
      for (int i = p * p; i <= n; i += p)
        prime[i] = false;
  prime[1] = 0;
}

int cnt, sum, mid, mx = -1e17, mn = 1e17;
int n, m, d, t, i, j, k, l, r, x, y, z;
bool f, f1, f2;
string s;
vi a(2 * LIM);
//*************************************************************************************************************************

int32_t main() {
  fio;
  cin >> n;
  forr(i, n) cin >> a[i];
  vi pre(LIM, 0), suff(LIM, 0);
  x = 0;
  forr(i, n) {
    pre[i] = x;
    x ^= a[i];
  }
  x = 0;
  for (i = n; i > 0; i--) {
    suff[i] = x;
    x ^= a[i];
  }
  forr(i, n) { cout << (pre[i] ^ suff[i]) << " "; }
}