Problem p02702 (C++) — buggy submission, verdict: Time Limit Exceeded

// SmartCoder
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update

using namespace __gnu_pbds;
using namespace std;

#define sz(a) int((a).size())
#define pb push_back
#define mp make_pair
#define all(c) (c).begin(), (c).end()
#define tr(c, i)                                                               \\
  for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); i++)
#define present(c, x) ((c).find(x) != (c).end())
#define cpresent(c, x) (find(all(c), x) != (c).end())
#define minei(x) min_element(x.begin(), x.end()) - (x).begin()
#define maxei(x) max_element(x.begin(), x.end()) - (x).begin()
#define LSOne(S) (S & (-S))

#define uns(v)                                                                 \\
  sort((v).begin(), (v).end()), v.erase(unique(v.begin(), v.end()), v.end())
#define acusum(x) accumulate(x.begin(), x.end(), 0)
#define acumul(x) accumulate(x.begin(), x.end(), 1, multiplies<int>());
#define bits(x) __builtin_popcount(x)
#define oo INT_MAX
#define inf 1000000000
#define MAXN 1000007
#define MOD 2019

const double pi = acos(-1.0);
const double eps = 1e-11;

typedef long long ll;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    indexed_set;

int main() {
  std::ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  string s;
  int cur = 0, d;
  cin >> s;
  int n = sz(s);
  ll res = 0;
  map<int, int> remCounter;
  remCounter[0] = 1;
  vector<int> powTen(n + 1);
  powTen[0] = 1;
  for (int i = 1; i <= n; i++) {
    powTen[i] = (powTen[i - 1] * 10) % MOD;
  }
  for (int i = 0; i < n; i++) {
    d = s[i] - '0';
    cur += (d * powTen[n - i - 1]);
    cur %= MOD;
    res += remCounter[cur];
    remCounter[cur]++;
  }
  cout << res << endl;
  return 0;
}


Error: TLE

Fixed submission:

// SmartCoder
#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update

using namespace __gnu_pbds;
using namespace std;

#define sz(a) int((a).size())
#define pb push_back
#define mp make_pair
#define all(c) (c).begin(), (c).end()
#define tr(c, i)                                                               \\
  for (__typeof((c).begin()) i = (c).begin(); i != (c).end(); i++)
#define present(c, x) ((c).find(x) != (c).end())
#define cpresent(c, x) (find(all(c), x) != (c).end())
#define minei(x) min_element(x.begin(), x.end()) - (x).begin()
#define maxei(x) max_element(x.begin(), x.end()) - (x).begin()
#define LSOne(S) (S & (-S))

#define uns(v)                                                                 \\
  sort((v).begin(), (v).end()), v.erase(unique(v.begin(), v.end()), v.end())
#define acusum(x) accumulate(x.begin(), x.end(), 0)
#define acumul(x) accumulate(x.begin(), x.end(), 1, multiplies<int>());
#define bits(x) __builtin_popcount(x)
#define oo INT_MAX
#define inf 1000000000
#define MAXN 1000007
#define MOD 2019

const double pi = acos(-1.0);
const double eps = 1e-11;

typedef long long ll;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;
typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    indexed_set;

int main() {
  std::ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  string s;
  int cur, d;
  cin >> s;
  int n = sz(s);
  ll res = 0;
  for (int i = 0; i < n; i++) {
    cur = 0;
    for (int j = i; j < min(50000, n); j++) {
      d = s[j] - '0';
      cur *= 10;
      cur += d;
      cur %= MOD;
      res += (cur == 0);
    }
  }
  cout << res << endl;
  return 0;
}