제출 #346712

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
346712		illequiprogrammat	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	1 ms	748 KiB

numbers

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;

typedef long long ll;

struct SOLUTION {
    bool vis[30][11][11][2][2];
    // memo[index][penultimate][end_digit][tight][notzeros];
    ll memo[30][11][11][2][2];

    vector<int> digits;

    SOLUTION() {
        memset(vis, 0, sizeof(vis));
        memset(memo, 0, sizeof(memo));
    }

    ll dp(int index, int penultimate, int end, bool tight, bool notzeros) {
        if (index == digits.size()) {
            if (notzeros) return 1;
            else return 0;
        }
        if (vis[index][penultimate][end][tight][notzeros])
            return memo[index][penultimate][end][tight][notzeros];


        ll res = 0;
        int max_next = 9;
        if (tight) max_next = digits[index];

        for (int i = 0; i <= max_next; i++) {
            if (i != penultimate && i != end) {
                int t_penultimate = end;
                int t_end = i;
                if (!notzeros && i == 0) t_end = 10;
                bool t_tight = tight && (i == max_next);
                bool t_notzeros = notzeros || (i > 0);
                res += dp(index + 1, t_penultimate, t_end, t_tight, t_notzeros);
            }
        }

        vis[index][penultimate][end][tight][notzeros] = true;
        memo[index][penultimate][end][tight][notzeros] = res;
        return res;
    }

    void get_digits(ll n) {
        while (n != 0) {
            digits.push_back(n%10);
            n /= 10;
        }
        reverse(digits.begin(), digits.end());
    }

    bool is_palindrome() {
        //cout << digits.size() << endl; 
        bool res = false;
        int i = 0;

        if (digits.size()>1)
            while (i < digits.size() - 1) {
                if (digits[i] == digits[i+1]) res = true;
                i++;
            }
        i = 0;

        if (digits.size() > 2)
            while (i < digits.size() - 2) {
                if (digits[i] == digits[i+2]) res = true;
                i++;
            }

        return res;
    }

};

int main() {
    ll a, b;
    SOLUTION l_bound;
    cin >> a >> b;
    if (a > b) swap(a, b);
    l_bound.get_digits(a-1);
    ll lres = -1;
    // index 0, allow all numbers inc 0, allow all numbers, tight = true
    if (a != 0) lres = l_bound.dp(0, 10, 10, true, false);
    SOLUTION u_bound;
    u_bound.get_digits(b);
    ll ures = u_bound.dp(0, 10, 10, true, false);
    //cout << lres << " " << ures << endl;
    cout << ures - lres << endl;
}

컴파일 시 표준 에러 (stderr) 메시지

numbers.cpp: In member function 'll SOLUTION::dp(int, int, int, bool, bool)':
numbers.cpp:22:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         if (index == digits.size()) {
      |             ~~~~~~^~~~~~~~~~~~~~~~
numbers.cpp: In member function 'bool SOLUTION::is_palindrome()':
numbers.cpp:64:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |             while (i < digits.size() - 1) {
      |                    ~~^~~~~~~~~~~~~~~~~~~
numbers.cpp:71:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |             while (i < digits.size() - 2) {
      |                    ~~^~~~~~~~~~~~~~~~~~~

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