Submission #832073

#	Time	Username	Problem	Language	Result	Execution time	Memory
832073		allw	Palindrome-Free Numbers (BOI13_numbers)	C++17	37.92 / 100	1 ms	340 KiB

numbers

#include <algorithm>
#include <cstdio>
#include <vector>
#include <iostream>
#include <map>
#include <cstring>

#define LOCAL true

/*
    Author: Oleksii Renov
*/

using namespace std;
using ll = long long int;

int dp[20][11][11][2][2];

ll run(int pos, int last1, int last2, bool smaller, bool started, const string& x) {
    if (pos == x.size()) {
        return 1;
    }

    if (dp[pos][last1][last2][smaller][started] != -1) {
        return dp[pos][last1][last2][smaller][started];
    }

    int end = smaller ? 9 : (x[pos] - '0');
    ll cnt = 0;
    for (int i = 0; i <= end; ++i) {
        if (!started && i == 0) continue;
        if (i != last1 && i != last2) {
            cnt += run(pos + 1, i, last1, smaller || (i != end), started || (i != 0), x);
        }
    }

    dp[pos][last1][last2][smaller][started] = cnt;
    return cnt;
}

int main() {
    ll a, b;
    cin >> a >> b;
    memset(dp, -1, sizeof(dp));
    ll cnt1 = run(0, 10, 10, false, false, to_string(b));
    memset(dp, -1, sizeof(dp));
    ll cnt2 = run(0, 10, 10, false, false, to_string(a-1));
    std::cout << cnt1 - cnt2 << '\n';
}

Compilation message (stderr)

numbers.cpp: In function 'll run(int, int, int, bool, bool, const string&)':
numbers.cpp:20:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     if (pos == x.size()) {
      |         ~~~~^~~~~~~~~~~

• Subtask 1: 11.25 / 25
• Subtask 2: 26.666666666666668 / 75