Submission #829130

#	Time	Username	Problem	Language	Result	Execution time	Memory
829130		arush_agu	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	388 KiB

numbers

#include <algorithm>
#include <cassert>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#ifdef DEBUG
#include <time.h>
#endif

#define all(a) (a).begin(), (a).end()
#define rev(a) (a).rbegin(), (a).rend()
#define F first
#define S second
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x)                                                                 \
  {                                                                            \
    ++recur_depth;                                                             \
    auto x_ = x;                                                               \
    --recur_depth;                                                             \
    cerr << string(recur_depth, '\t') << "\e[91m" << __func__ << ":"           \
         << __LINE__ << "\t" << #x << " = " << x_ << "\e[39m" << endl;         \
  }
#else
#define dbg(x)
#endif

using namespace std;
using namespace __gnu_pbds;

typedef pair<int, int> ii;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> llll;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vii;
typedef vector<vii> vvii;

typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pair<ll, ll>> vll;
typedef vector<vll> vvll;

typedef vector<bool> vb;

template <class type1>
using ordered_set = tree<type1, null_type, less<type1>, rb_tree_tag,
                         tree_order_statistics_node_update>;

template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
  return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<
                                    !is_same<T_container, string>::value,
                                    typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v) {
  os << '{';
  string sep;
  for (const T &x : v)
    os << sep << x, sep = ", ";
  return os << '}';
}

const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll INF = 1e9;
const ld EPS = 1e-9;

void solve() {
  ll a, b;
  cin >> a >> b;

  a--;
  string sa = to_string(a), sb = to_string(b);

  auto do_it = [](string s) {
    if (s == "0")
      return 1LL;

    int no_digs = s.size();
    ll dp[no_digs + 1][11][11][2][2];
    memset(dp, -1, sizeof(dp));

    function<ll(int, int, int, int, int)> f = [&](int digit, int np1, int np2,
                                                  int mx, int zero) -> ll {
      assert(digit <= no_digs);
      assert(np1 <= 10 && np2 <= 10);
      assert(mx == 0 || mx == 1);
      assert(zero == 0 || zero == 1);

      ll upper = 9;
      if (mx)
        upper = s[digit] - '0';

      if (digit == no_digs - 1) {
        // cerr << "\t\t" << "Digit: " << digit << " Np1: " << np1 << " Np2: "
        // << np2 << " MX: " << mx << " Z: " << zero << "\n";
        ll ans = 0;
        for (int i = 0; i <= upper; i++)
          if (i != np1 && i != np2)
            ans++;
        // cerr << "\t\t\tA: " << ans << "\n";
        return ans;
      }

      ll &x = dp[digit][np1][np2][mx][zero];
      if (x != -1)
        return x;

      // cerr << "Digit: " << digit << " Np1: " << np1 << " Np2: " << np2 << "
      // MX: " << mx << " Z: " << zero << "\n";

      x = 0;
      if (zero)
        x += f(digit + 1, 10, 10, 0, 1);
      else if (np1 != 0 && np2 != 0)
        x += f(digit + 1, np2, 0, mx && (s[digit] == '0'), 0);
      // cerr << "\tD: " << digit << " placing 0 getting " << x << "\n";
      for (int i = 1; i <= upper; i++)
        if (i != np1 && i != np2) {
          // ll y = f(digit + 1, np2, i, mx && (upper == i), 0);
          // cerr << "\tD: " << digit << " placing: " << i << " getting " << y
          // << "\n";
          x += f(digit + 1, np2, i, mx && (upper == i), 0);
        }
      return x;
    };

    return f(0, 10, 10, 1, 1);
  };

  if (a == -1) {
    cout << do_it(sb) << "\n";
    return;
  }

  cout << do_it(sb) - do_it(sa) << "\n";
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);

  clock_t start = clock();

  int test_cases = 1;
  /* cin >> test_cases; */

  while (test_cases--)
    solve();

#ifdef DEBUG
  cerr << fixed << setprecision(10)
       << "\nTime Taken: " << (double)(clock() - start) / CLOCKS_PER_SEC
       << "s\n";
#endif
  return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'int main()':
numbers.cpp:167:11: warning: unused variable 'start' [-Wunused-variable]
  167 |   clock_t start = clock();
      |           ^~~~~

• Subtask 1: 25 / 25
• Subtask 2: 75 / 75