Submission #1052805

#	Time	Username	Problem	Language	Result	Execution time	Memory
1052805		ortsac	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	604 KiB

numbers

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

#define int long long

const int MAXN = 19;
int dp[MAXN][2][11][11];

string s;

int d(int i) {
    return (s[i] - '0');
}

int calc(int x) {
    if (x < 1) return x + 1;
    s = to_string(x);
    int tam = s.size();
    reverse(s.begin(), s.end());
    memset(dp, 0, sizeof dp);
    for (int i = 0; i <= 9; i++) dp[0][1][i][10] = 1;
    for (int i = 0; i <= d(0); i++) dp[0][0][i][10] = 1;
    for (int i = 1; i < tam; i++) {
        // calc 1
        for (int a = 0; a <= 9; a++) {
            for (int b = 0; b <= 9; b++) {
                for (int c = 0; c <= 10; c++) {
                    if ((a == b) || (a == c)) continue;
                    dp[i][1][a][b] += dp[i - 1][1][b][c];
                }
            }
        }
        // calc 0
        for (int a = 0; a < d(i); a++) {
            for (int b = 0; b <= 9; b++) {
                for (int c = 0; c <= 10; c++) {
                    if ((a == b) || (a == c)) continue;
                    dp[i][0][a][b] += dp[i - 1][1][b][c];
                }
            }
        }
        int a = d(i);
        for (int b = 0; b <= 9; b++) {
            for (int c = 0; c <= 10; c++) {
                if ((a == b) || (a == c)) continue;
                dp[i][0][a][b] += dp[i - 1][0][b][c];
            }
        }
    }
    int ans = 1;
    for (int i = 0; i < (tam - 1); i++) {
        for (int b = 1; b <= 10; b++) {
            for (int c = 0; c <= 10; c++) {
                ans += dp[i][1][b][c];
            }
        }
    }
    for (int b = 1; b <= 10; b++) {
        for (int c = 0; c <= 10; c++) {
            ans += dp[tam - 1][0][b][c];
            //cout << b << " " << c << " " << dp[tam - 1][0][b][c] << "\n";
        }
    }
    return ans;
}

int32_t main() {
    int a, b;
    cin >> a >> b;
    cout << calc(b) - calc(a - 1) << "\n";
}

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