Problem p02609 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
const int mod = 1e9 + 7;

struct mint {
  ll x; // typedef long long ll;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}

  mint operator-() const { return mint(-x); }

  mint &operator+=(const mint a) {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }

  mint &operator-=(const mint a) {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }

  mint &operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }

  mint operator+(const mint a) const { return mint(*this) += a; }

  mint operator-(const mint a) const { return mint(*this) -= a; }

  mint operator*(const mint a) const { return mint(*this) *= a; }

  mint pow(ll t) const {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const { return pow(mod - 2); }

  mint &operator/=(const mint a) { return *this *= a.inv(); }

  mint operator/(const mint a) const { return mint(*this) /= a; }
};

istream &operator>>(istream &is, const mint &a) { return is >> a.x; }

ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }

struct combination {
  vector<mint> fact, ifact;

  combination(int n) : fact(n + 1), ifact(n + 1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i)
      fact[i] = fact[i - 1] * i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i)
      ifact[i - 1] = ifact[i] * i;
  }

  mint operator()(int n, int k) {
    if (k < 0 || k > n)
      return 0;
    return fact[n] * ifact[k] * ifact[n - k];
  }
};

struct UnionFind {
  vector<int> d;

  UnionFind(int n = 0) : d(n, -1) {}

  int find(int x) {
    if (d[x] < 0)
      return x;
    return d[x] = find(d[x]);
  }

  bool unite(int x, int y) {
    x = find(x);
    y = find(y);
    if (x == y)
      return false;
    if (d[x] > d[y])
      swap(x, y);
    d[x] += d[y];
    d[y] = x;
    return true;
  }

  bool same(int x, int y) { return find(x) == find(y); }

  int size(int x) { return -d[find(x)]; }
};

template <typename T> struct BIT {
  int n;
  vector<T> bit[2];

  BIT(int n_) { init(n_); }

  void init(int n_) {
    n = n_ + 1;
    for (int p = 0; p < 2; p++)
      bit[p].assign(n, 0);
  }

  void add_sub(int p, int i, T x) {
    for (int idx = i; idx < n; idx += (idx & -idx)) {
      bit[p][idx] += x;
    }
  }

  void add(int l, int r, T x) {
    add_sub(0, l, -x * (l - 1));
    add_sub(0, r, x * (r - 1));
    add_sub(1, l, x);
    add_sub(1, r, -x);
  }

  T sum_sub(int p, int i) {
    T s(0);
    for (int idx = i; idx > 0; idx -= (idx & -idx)) {
      s += bit[p][idx];
    }
    return s;
  }

  T sum(int i) { return sum_sub(0, i) + sum_sub(1, i) * i; }
};

ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }

ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

int main() {
  int n;
  string s;
  cin >> n >> s;
  int one = 0;
  for (int i = 0; i < n; ++i)
    if (s[i] == '1')
      one++;
  vector<ll> A(n + 10), B(n + 10);
  ll f = 0, b = 0;
  A[0] = B[0] = 1;
  for (int i = 0; i < n; ++i) {
    A[i + 1] = A[i] * 2 % (one + 1);
    if (one - 1 > 0)
      B[i + 1] = B[i] * 2 % (one - 1);
  }
  for (int i = 0; i < n; ++i) {
    if (s[n - i - 1] == '1') {
      f = (f + A[i]) % (one + 1);
      if (one - 1 > 0)
        b = (b + B[i]) % (one - 1);
    }
  }
  for (int i = 0; i < n; ++i) {
    ll p = 0;
    if (s[i] == '0') {
      p = (f + A[n - i - 1]) % (one + 1);
    } else {
      if (one - 1 == 0) {
        cout << 0 << endl;
        continue;
      }
      p = (b - B[n - i - 1]);
      if (p < 0)
        p += (one - 1);
      p %= (one - 1);
    }
    int c = 0;
    while (p > 0)
      p %= bitset<1000>(p).count(), c++;
    cout << c + 1 << endl;
  }
  return 0;
}


Error: WA

Fixed submission:

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
const int mod = 1e9 + 7;

struct mint {
  ll x; // typedef long long ll;
  mint(ll x = 0) : x((x % mod + mod) % mod) {}

  mint operator-() const { return mint(-x); }

  mint &operator+=(const mint a) {
    if ((x += a.x) >= mod)
      x -= mod;
    return *this;
  }

  mint &operator-=(const mint a) {
    if ((x += mod - a.x) >= mod)
      x -= mod;
    return *this;
  }

  mint &operator*=(const mint a) {
    (x *= a.x) %= mod;
    return *this;
  }

  mint operator+(const mint a) const { return mint(*this) += a; }

  mint operator-(const mint a) const { return mint(*this) -= a; }

  mint operator*(const mint a) const { return mint(*this) *= a; }

  mint pow(ll t) const {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime mod
  mint inv() const { return pow(mod - 2); }

  mint &operator/=(const mint a) { return *this *= a.inv(); }

  mint operator/(const mint a) const { return mint(*this) /= a; }
};

istream &operator>>(istream &is, const mint &a) { return is >> a.x; }

ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }

struct combination {
  vector<mint> fact, ifact;

  combination(int n) : fact(n + 1), ifact(n + 1) {
    assert(n < mod);
    fact[0] = 1;
    for (int i = 1; i <= n; ++i)
      fact[i] = fact[i - 1] * i;
    ifact[n] = fact[n].inv();
    for (int i = n; i >= 1; --i)
      ifact[i - 1] = ifact[i] * i;
  }

  mint operator()(int n, int k) {
    if (k < 0 || k > n)
      return 0;
    return fact[n] * ifact[k] * ifact[n - k];
  }
};

struct UnionFind {
  vector<int> d;

  UnionFind(int n = 0) : d(n, -1) {}

  int find(int x) {
    if (d[x] < 0)
      return x;
    return d[x] = find(d[x]);
  }

  bool unite(int x, int y) {
    x = find(x);
    y = find(y);
    if (x == y)
      return false;
    if (d[x] > d[y])
      swap(x, y);
    d[x] += d[y];
    d[y] = x;
    return true;
  }

  bool same(int x, int y) { return find(x) == find(y); }

  int size(int x) { return -d[find(x)]; }
};

template <typename T> struct BIT {
  int n;
  vector<T> bit[2];

  BIT(int n_) { init(n_); }

  void init(int n_) {
    n = n_ + 1;
    for (int p = 0; p < 2; p++)
      bit[p].assign(n, 0);
  }

  void add_sub(int p, int i, T x) {
    for (int idx = i; idx < n; idx += (idx & -idx)) {
      bit[p][idx] += x;
    }
  }

  void add(int l, int r, T x) {
    add_sub(0, l, -x * (l - 1));
    add_sub(0, r, x * (r - 1));
    add_sub(1, l, x);
    add_sub(1, r, -x);
  }

  T sum_sub(int p, int i) {
    T s(0);
    for (int idx = i; idx > 0; idx -= (idx & -idx)) {
      s += bit[p][idx];
    }
    return s;
  }

  T sum(int i) { return sum_sub(0, i) + sum_sub(1, i) * i; }
};

ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }

ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

int main() {
  int n;
  string s;
  cin >> n >> s;
  int one = 0;
  for (int i = 0; i < n; ++i)
    if (s[i] == '1')
      one++;
  vector<ll> A(n + 10), B(n + 10);
  ll f = 0, b = 0;
  A[0] = B[0] = 1;
  for (int i = 0; i < n; ++i) {
    A[i + 1] = A[i] * 2 % (one + 1);
    B[i + 1] = B[i] * 2 % max(0, one - 1);
  }
  for (int i = 0; i < n; ++i) {
    if (s[n - i - 1] == '1') {
      f = (f + A[i]) % (one + 1);
      b = (b + B[i]) % max(0, one - 1);
    }
  }
  for (int i = 0; i < n; ++i) {
    ll p = 0;
    if (s[i] == '0') {
      p = (f + A[n - i - 1]) % (one + 1);
    } else {
      p = (b - B[n - i - 1]);
      if (p < 0)
        p += max(0, one - 1);
      p %= max(0, one - 1);
    }
    cout << p << endl;
    int c = 0;
    while (p > 0)
      p %= bitset<1000>(p).count(), c++;
    cout << c + 1 << endl;
  }
  return 0;
}