Submission #1075741

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075741		ShadowShark	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	604 KiB

numbers

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

long long dp[20][11][11][2][2];
vector<int> num;

long long calc(int pos, int pre1, int pre2, int f, int leading_0) {
    if (pos == num.size()) return 1;

    if (dp[pos][pre1][pre2][f][leading_0] != -1) return dp[pos][pre1][pre2][f][leading_0];

    long long res = 0; int M = (f == 1 ? 9 : num[pos]);

    for (int i = 0; i <= M; i++) {
        int F = f;
        if (F == 0 && i < M) F = 1;

        if (leading_0) {
            if (i == pre1 || i == pre2) continue;
            res = res + calc(pos + 1, pre2, i, F, 1);
        }
        else {
            if (i == 0) res = res + calc(pos + 1, pre1, pre2, F, 0);
                else res = res + calc(pos + 1, pre1, i, F, 1);
        }
    }

    return dp[pos][pre1][pre2][f][leading_0] = res;
}

long long solve(long long x) {
    num.clear();
    memset(dp, -1, sizeof dp);

    while (x > 0) {
        num.push_back(x % 10);
        x = x / 10;
    }

    reverse(num.begin(), num.end());

    return calc(0, 10, 10, 0, 0);
}

int main() {
    long long a, b;
    cin >> a >> b;

    cout << solve(b) - solve(a - 1) + (a == 0 ? 1 : 0);
    return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'long long int calc(int, int, int, int, int)':
numbers.cpp:8:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     if (pos == num.size()) return 1;
      |         ~~~~^~~~~~~~~~~~~

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