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

// #include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> p;
const ll INF = 1e9;
const ll LINF = ll(1e18);
const ll MOD = 1000000007;
const ll dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const ll Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1},
         Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (ll i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)                                                               \\
  cout << #v << ":";                                                           \\
  for (auto x : v) {                                                           \\
    cout << x << ' ';                                                          \\
  }                                                                            \\
  cout << endl;
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
// cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//-std=gnu++17
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; }
ll modp, modm;
string s;
ll mpow(ll x, ll n, ll M) { // x^n(mod M)
  ll ans = 1;
  while (n != 0) {
    if (n & 1)
      ans = ans * x % M;
    x = x * x % M;
    n = n >> 1;
  }
  return ans;
}
ll calc(ll m) {
  ll res = 0;
  while (m) {
    ll popc = __builtin_popcount(m);
    m %= popc;
    res++;
  }
  return res;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n;
  cin >> n >> s;
  ll countt = 0;
  rep(i, n) {
    if (s[i] == '1')
      countt++;
  }
  ll count = countt;
  countt++;
  modp = 0;
  if (countt != 0) {
    rep(i, n) {
      modp *= 2;
      if (s[i] == '1')
        modp++;
      modp %= countt;
    }
  }
  countt -= 2;
  modm = 0;
  if (countt != 0) {
    rep(i, n) {
      modm *= 2;
      if (s[i] == '1')
        modm++;
      modm %= countt;
    }
  }
  countt++;
  for (ll i = 0; i < n; i++) {
    if (s[i] == '0') {
      s[i] = '1';
      count++;
    } else {
      s[i] = '0';
      count--;
    }
    ll m;
    if (count == 0) {
      cout << 0 << "\\n";
    } else {
      if (count > countt) {
        m = modp;
        m += mpow(2, n - 1 - i, count);
        m %= count;
      } else {
        m = modm;
        m -= mpow(2, n - 1 - i, count);
        m += count;
        m %= count;
      }
      // cout<<m<<"\\n";
      cout << calc(m) + 1 << "\\n";
    }
    if (s[i] == '0') {
      s[i] = '1';
      count++;
    } else {
      s[i] = '0';
      count--;
    }
  }
}


Error: 0

Fixed submission:

// #include <tourist>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> p;
const ll INF = 1e9;
const ll LINF = ll(1e18);
const ll MOD = 1000000007;
const ll dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const ll Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1},
         Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (ll i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)                                                               \\
  cout << #v << ":";                                                           \\
  for (auto x : v) {                                                           \\
    cout << x << ' ';                                                          \\
  }                                                                            \\
  cout << endl;
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
// cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//-std=gnu++17
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; }
ll modp, modm;
string s;
ll mpow(ll x, ll n, ll M) { // x^n(mod M)
  ll ans = 1;
  while (n != 0) {
    if (n & 1)
      ans = ans * x % M;
    x = x * x % M;
    n = n >> 1;
  }
  return ans;
}
ll calc(ll m) {
  ll res = 0;
  while (m) {
    ll popc = __builtin_popcount(m);
    m %= popc;
    res++;
  }
  return res;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n;
  cin >> n >> s;
  ll countt = 0;
  rep(i, n) {
    if (s[i] == '1')
      countt++;
  }
  ll count = countt;
  countt++;
  modp = 0;
  rep(i, n) {
    modp *= 2;
    if (s[i] == '1')
      modp++;
    modp %= countt;
  }
  countt -= 2;
  modm = 0;
  rep(i, n) {
    modm *= 2;
    if (s[i] == '1')
      modm++;
    modm %= countt;
  }
  countt++;
  for (ll i = 0; i < n; i++) {
    if (s[i] == '0') {
      s[i] = '1';
      count++;
    } else {
      s[i] = '0';
      count--;
    }
    ll m;
    if (count == 0) {
      cout << 0 << "\\n";
    } else {
      if (count > countt) {
        m = modp;
        m += mpow(2, n - 1 - i, count);
        m %= count;
      } else {
        m = modm;
        m -= mpow(2, n - 1 - i, count);
        m += count;
        m %= count;
      }
      // cout<<m<<"\\n";
      cout << calc(m) + 1 << "\\n";
    }
    if (s[i] == '0') {
      s[i] = '1';
      count++;
    } else {
      s[i] = '0';
      count--;
    }
  }
}