Problem p02548 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define mp make_pair
#define pu push
#define pp pop_back
#define in insert
#define forn(low, high, i) for (i = low; i < high; i++)
#define forrev(high, low, i)                                                   \\
  for (i = high; i >= low; i--)           // g++ ll.cpp -o ll.exe
#define zeroes(x) memset(x, 0, sizeof(x)) // all elements to 0
#define all(x) (x).begin(), (x).end()
typedef long long int ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
const ll mod = 1e9 + 7;
const ll maxn = 100000;

bool sortbysec(const pair<int, int> &a, // sorting of elements wrt second
               const pair<int, int> &b) {
  return (a.second < b.second);
}

void SieveOfEratosthenes(ll n, bool prime[], bool primesquare[], ll a[]) {
  // Create a boolean array "prime[0..n]" and
  // initialize all entries it as true. A value
  // in prime[i] will finally be false if i is
  // Not a prime, else true.
  for (ll i = 2; i <= n; i++)
    prime[i] = true;

  // Create a boolean array "primesquare[0..n*n+1]"
  // and initialize all entries it as false. A value
  // in squareprime[i] will finally be true if i is
  // square of prime, else false.
  for (ll i = 0; i <= (2 * n); i++)
    primesquare[i] = false;

  // 1 is not a prime number
  prime[1] = false;

  for (ll p = 2; p * p <= n; p++) {
    // If prime[p] is not changed, then
    // it is a prime
    if (prime[p] == true) {
      // Update all multiples of p
      for (ll i = p * 2; i <= n; i += p)
        prime[i] = false;
    }
  }

  ll j = 0;
  for (ll p = 2; p <= n; p++) {
    if (prime[p]) {
      // Storing primes in an array
      a[j] = p;

      // Update value in primesquare[p*p],
      // if p is prime.
      if (p * p < (2 * n))
        primesquare[p * p] = true;
      j++;
    }
  }
}

// Function to count divisors
int countDivisors(ll n, ll a[], bool prime[], bool primesquare[]) {
  // If number is 1, then it will have only 1
  // as a factor. So, total factors will be 1.
  if (n == 1)
    return 1;

  // ans will contain total number of distinct
  // divisors
  ll ans = 1;

  // Loop for counting factors of n
  for (ll i = 0;; i++) {
    // a[i] is not less than cube root n
    if (a[i] * a[i] * a[i] > n)
      break;

    // Calculating power of a[i] in n.
    ll cnt = 1;           // cnt is power of prime a[i] in n.
    while (n % a[i] == 0) // if a[i] is a factor of n
    {
      n = n / a[i];
      cnt = cnt + 1; // incrementing power
    }

    // Calculating the number of divisors
    // If n = a^p * b^q then total divisors of n
    // are (p+1)*(q+1)
    ans = ans * cnt;
  }

  // if a[i] is greater than cube root of n

  // First case
  if (prime[n])
    ans = ans * 2;

  // Second case
  else if (primesquare[n])
    ans = ans * 3;

  // Third case
  else if (n != 1)
    ans = ans * 4;

  return ans; // Total divisors
}

int main() {
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif

  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);

  ll n;
  cin >> n;

  bool prime[n + 1], primesquare[2 * n];
  ll a[n];

  SieveOfEratosthenes(n, prime, primesquare, a);

  ll sum1 = 1, sum;
  for (ll i = 2; i < n; ++i) {
    sum = countDivisors(i, a, prime, primesquare);
    /*sum+=sum;
    long double p;
    p=sqrt(i);
    if(p==(ll)p)
        sum--;*/

    sum1 += sum;
  }

  cout << sum1;

  return 0;
}

Error: -11

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define mp make_pair
#define pu push
#define pp pop_back
#define in insert
#define forn(low, high, i) for (i = low; i < high; i++)
#define forrev(high, low, i)                                                   \\
  for (i = high; i >= low; i--)           // g++ ll.cpp -o ll.exe
#define zeroes(x) memset(x, 0, sizeof(x)) // all elements to 0
#define all(x) (x).begin(), (x).end()
typedef long long int ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
const ll mod = 1e9 + 7;
const ll maxn = 100000;

bool sortbysec(const pair<int, int> &a, // sorting of elements wrt second
               const pair<int, int> &b) {
  return (a.second < b.second);
}

void SieveOfEratosthenes(ll n, bool prime[], bool primesquare[], ll a[]) {
  // Create a boolean array "prime[0..n]" and
  // initialize all entries it as true. A value
  // in prime[i] will finally be false if i is
  // Not a prime, else true.
  for (ll i = 2; i <= n; i++)
    prime[i] = true;

  // Create a boolean array "primesquare[0..n*n+1]"
  // and initialize all entries it as false. A value
  // in squareprime[i] will finally be true if i is
  // square of prime, else false.
  for (ll i = 0; i <= (n * n + 1); i++)
    primesquare[i] = false;

  // 1 is not a prime number
  prime[1] = false;

  for (ll p = 2; p * p <= n; p++) {
    // If prime[p] is not changed, then
    // it is a prime
    if (prime[p] == true) {
      // Update all multiples of p
      for (ll i = p * 2; i <= n; i += p)
        prime[i] = false;
    }
  }

  ll j = 0;
  for (ll p = 2; p <= n; p++) {
    if (prime[p]) {
      // Storing primes in an array
      a[j] = p;

      // Update value in primesquare[p*p],
      // if p is prime.
      primesquare[p * p] = true;
      j++;
    }
  }
}

// Function to count divisors
int countDivisors(ll n, ll a[], bool prime[], bool primesquare[]) {
  // If number is 1, then it will have only 1
  // as a factor. So, total factors will be 1.
  if (n == 1)
    return 1;

  // ans will contain total number of distinct
  // divisors
  ll ans = 1;

  // Loop for counting factors of n
  for (ll i = 0;; i++) {
    // a[i] is not less than cube root n
    if (a[i] * a[i] * a[i] > n)
      break;

    // Calculating power of a[i] in n.
    ll cnt = 1;           // cnt is power of prime a[i] in n.
    while (n % a[i] == 0) // if a[i] is a factor of n
    {
      n = n / a[i];
      cnt = cnt + 1; // incrementing power
    }

    // Calculating the number of divisors
    // If n = a^p * b^q then total divisors of n
    // are (p+1)*(q+1)
    ans = ans * cnt;
  }

  // if a[i] is greater than cube root of n

  // First case
  if (prime[n])
    ans = ans * 2;

  // Second case
  else if (primesquare[n])
    ans = ans * 3;

  // Third case
  else if (n != 1)
    ans = ans * 4;

  return ans; // Total divisors
}

int main() {
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif

  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);

  ll n;
  cin >> n;

  bool prime[n + 1], primesquare[n * n + 1];
  ll a[n];

  SieveOfEratosthenes(n, prime, primesquare, a);

  ll sum1 = 1, sum;
  for (ll i = 2; i < n; ++i) {
    sum = countDivisors(i, a, prime, primesquare);
    /*sum+=sum;
    long double p;
    p=sqrt(i);
    if(p==(ll)p)
        sum--;*/

    sum1 += sum;
  }

  cout << sum1;

  return 0;
}