Submission #1097880

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097880		Alihan_8	Palindrome-Free Numbers (BOI13_numbers)	C++17	72.50 / 100	1 ms	604 KiB

numbers

#include <bits/stdc++.h>

using namespace std;

using i64 = long long;

signed main(){
	i64 a, b; cin >> a >> b;
	
	auto f = [&](i64 x) -> i64{
		if ( x < 0 ) return 0;
		
		string s = to_string(x);
		int n = s.size();
		
		for ( auto &x: s ) x -= '0';
		
		i64 dp[n][11][11][2]{};
		
		for ( int j = 0; j <= s[0]; j++ ){
			dp[0][10][j][j < s[0]] = 1;
		}
		
		for ( int i = 1; i < n; i++ ){
			for ( int j = 0; j <= 10; j++ ){
				for ( int k = 0; k <= 10; k++ ){
					for ( int c = 0; c <= 9; c++ ){
						if ( c == k || c == j ) continue;
						
						for ( auto l: {0, 1} ){
							if ( !l && c > s[i] ) continue;
							
							int nxt = l || (c < s[i]);
							
							dp[i][k][c][nxt] += dp[i - 1][j][k][l];
						}
					}
				}
			}
		}
		
		i64 cnt = 0;
		
		for ( int x = 0; x <= 10; x++ ){
			for ( int y = 0; y <= 10; y++ ){
				for ( auto f: {0, 1} ){
					cnt += dp[n - 1][x][y][f];
				}
			}
		}
		
		return cnt;
	};
	
	cout << f(b) - f(a - 1) << endl;
}

• Subtask 1: 12.5 / 25
• Subtask 2: 60 / 75