Submission #522417

#	Time	Username	Problem	Language	Result	Execution time	Memory
522417		Hamed5001	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	1 ms	460 KiB

numbers

#include <bits/stdc++.h>
using namespace std;

long long dp[19][11][11][2][2];

long long fun(int idx, string &s, pair<int, int> last, bool lz, bool sm) {
    if (idx == s.size()) return 1;
    
    auto &ret = dp[idx][last.first][last.second][lz][sm];
    if (~ret) return ret;
    
    ret = 0;
    if (lz) ret += fun(idx + 1, s, last, 1, 1);
    for (int i = 0; i < 10; ++i) {
        if (lz && i == 0) continue;
        if (i == last.first || i == last.second) continue;
        if (i <= s[idx] - '0' || sm)
            ret += fun(idx + 1, s, {i, last.first}, 0, sm | (i < s[idx] - '0')); 
    }
    return ret;
}

long long calc(long long limit) {
    if (limit < 0) return 0;
    string s = to_string(limit);
    memset(dp, -1, sizeof dp);
    return fun(0, s, {10, 10}, 1, 0);
}

void solve() {
    long long l, r;
    cin >> l >> r;
    cout << calc(r) - calc(l - 1);
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	solve();
	return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'long long int fun(int, std::string&, std::pair<int, int>, bool, bool)':
numbers.cpp:7:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |     if (idx == s.size()) return 1;
      |         ~~~~^~~~~~~~~~~

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