Submission #900244

#	Time	Username	Problem	Language	Result	Execution time	Memory
900244		theghostking	Palindrome-Free Numbers (BOI13_numbers)	C++17	71.25 / 100	1 ms	600 KiB

numbers

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

#define int long long

vector<int> num;

int dp[20][12][12][2];
//pos, last digit, last last digit, tight
//11 -> no digit

int call(int pos, int lst, int lslst, int f){
    if (pos == num.size()){
        return 1;
    }
    if (dp[pos][lst][lslst][f] != -1) return dp[pos][lst][lslst][f];
    int res = 0;
    int lmt = 0;
    if (f == 0){
        lmt = num[pos];
    }
    else{
        lmt = 9;
    }
    for (int dgt = 0; dgt <= lmt; dgt++){
        if (dgt == lst || dgt == lslst) continue;
        int nf = f;
        if (f == 0 && dgt < lmt) nf = 1;
        res += call(pos+1,dgt,lst,nf);
    }
    return dp[pos][lst][lslst][f] = res;
}

int solve(int b){
    num.clear();
    while (b > 0){
        num.push_back(b%10);
        b /= 10;
    }
    reverse(num.begin(),num.end());
    memset(dp,-1,sizeof(dp));
    int res = call(0,11,11,0);
    return res;
}

signed main() {
    int a,b;
    cin >> a >> b;
    cout << solve(b)-solve(a-1);
    return 0;
}

Compilation message (stderr)

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

• Subtask 1: 11.25 / 25
• Subtask 2: 60 / 75