Problem p02702 (C++) — buggy submission, verdict: Runtime Error

// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// #include <bits/stdc++.h>
#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <valarray>
#include <vector>
using namespace std;
#define IOS                                                                    \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);                                                               \\
  cout.tie(NULL);
#define trace(x) cerr << #x << ": " << x << " " << endl;

typedef int64_t ll;

#define endl '\\n'
#define int ll
ll mod = 998244353;
ll mod1 = 1e9 + 5;
ll power(ll a, ll b) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return power(((((a) % mod) * ((a) % mod)) % mod), b / 2) % mod;
  else
    return (((a) % mod) *
            (power(((((a) % mod) * ((a) % mod)) % mod), b / 2) % mod)) %
           mod;
}
inline ll inverse(ll a, ll md) {
  a %= md;
  if (a < 0)
    a += md;
  ll b = md, u = 0, v = 1;
  while (a) {
    ll t = b / a;
    b -= t * a;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  assert(b == 1);
  if (u < 0)
    u += md;
  return u;
}

// using namespace __gnu_pbds;
// #define ordered_set tree<pair<int,int>, null_type,less<pair<int,int>>,
// rb_tree_tag,tree_order_statistics_node_update>
// find_by_order(k)  returns iterator to kth element starting from 0;
// order_of_key(k) returns count of elements strictly smaller than k;
// erase,insert same as normal set
//  mt19937
//  mrand(chrono::high_resolution_clock::now().time_since_epoch().count()); for
//  randomized solution
const int ce = 998244353;
ll fast_mod(ll input) { return input < ce ? input : input % ce; }
#define pi acos(-1)

int32_t main() {
  IOS

      string s;
  cin >> s;
  int n = s.length();
  int dp[2][2019];
  memset(dp, 0, sizeof(dp));

  dp[0][s[0] - '0']++;
  int ans = 0;
  for (int i = 1; i < n; i++) {
    int num = s[i] - '0';
    if (i % 2 != 0) {
      for (int j = 0; j < 2019; j++) {
        dp[1][j] = 0;
      }
    } else {
      for (int j = 0; j < 2019; j++) {
        dp[0][j] = 0;
      }
    }
    for (int j = 0; j < 2019; j++) {
      if (i % 2 != 0)
        dp[1][(j * 10 + num) % 2019] += dp[0][j];
      else
        dp[0][(j * 10 + num) % 2019] += dp[1][j];
    }
    if (i % 2 != 0)
      dp[1][num]++;
    else
      dp[0][num]++;
    if (i % 2 != 0)
      ans += dp[1][0];
    else
      ans += dp[0][0];
  }
  cout << ans << endl;
}


Error: 0

Fixed submission:

// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// #include <bits/stdc++.h>
#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <valarray>
#include <vector>
using namespace std;
#define IOS                                                                    \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);                                                               \\
  cout.tie(NULL);
#define trace(x) cerr << #x << ": " << x << " " << endl;

typedef int64_t ll;

#define endl '\\n'
#define int ll
ll mod = 998244353;
ll mod1 = 1e9 + 5;
ll power(ll a, ll b) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return power(((((a) % mod) * ((a) % mod)) % mod), b / 2) % mod;
  else
    return (((a) % mod) *
            (power(((((a) % mod) * ((a) % mod)) % mod), b / 2) % mod)) %
           mod;
}
inline ll inverse(ll a, ll md) {
  a %= md;
  if (a < 0)
    a += md;
  ll b = md, u = 0, v = 1;
  while (a) {
    ll t = b / a;
    b -= t * a;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  assert(b == 1);
  if (u < 0)
    u += md;
  return u;
}

// using namespace __gnu_pbds;
// #define ordered_set tree<pair<int,int>, null_type,less<pair<int,int>>,
// rb_tree_tag,tree_order_statistics_node_update>
// find_by_order(k)  returns iterator to kth element starting from 0;
// order_of_key(k) returns count of elements strictly smaller than k;
// erase,insert same as normal set
//  mt19937
//  mrand(chrono::high_resolution_clock::now().time_since_epoch().count()); for
//  randomized solution
const int ce = 998244353;
ll fast_mod(ll input) { return input < ce ? input : input % ce; }
#define pi acos(-1)

int32_t main() {
  IOS

      string s;
  cin >> s;
  int n = s.length();
  int dp[n + 1][2019];
  memset(dp, 0, sizeof(dp));
  dp[0][s[0] - '0']++;
  int ans = 0;
  for (int i = 1; i < n; i++) {
    int num = s[i] - '0';
    for (int j = 0; j < 2019; j++) {
      dp[i][(j * 10 + num) % 2019] += dp[i - 1][j];
    }
    dp[i][num]++;
    ans += dp[i][0];
  }
  cout << ans << endl;
}