Submission #488474

#	Time	Username	Problem	Language	Result	Execution time	Memory
488474		NintsiChkhaidze	Palindrome-Free Numbers (BOI13_numbers)	C++14	96.25 / 100	1 ms	344 KiB

numbers

#include <bits/stdc++.h>
#define pb push_back
#define s second
#define f first
#define ll long long
#define int ll
using namespace std;
 
string str;
int dp[15][15][25][5],SIZE;

int get(int last2,int last,int len,int sm){
    if (len >= SIZE) return 1;
    if (dp[last2][last][len][sm] != -1) 
        return dp[last2][last][len][sm];
    
    int l = str[len] - '0',sum = 0;
    if (sm){
        for (int i = 0; i <= 9; i++){
            if (i != last && i != last2)
                sum += get(last,i,len + 1,1);
        }
    }
    else{
        for (int i = 0; i < l; i++){
            if (i != last && i != last2)
                sum += get(last,i,len + 1,1);
        }
        
        if (l != last && l != last2)
            sum += get(last,l,len + 1,0);    
    }
    return dp[last2][last][len][sm] = sum;
}
void clear(){
    for (int i = 0; i <= 9; i++)
        for (int j = 0; j <= 9; j++)
            for (int z = 0; z<=20; z++)
                dp[i][j][z][0] = dp[i][j][z][1] = -1;
}
int G(int x){
    if (x <= 0) return 0;
    clear();
    str = "";
    while(x){
        str+=(x%10)+'0';
        x/=10;
    }
    
    reverse(str.begin(),str.end());
    int l = str[0] - '0',ans = 0;
    SIZE = str.size();
    for (int i = 1; i < l; i++)
        ans += get(i,i,1,1);
    
    ans += get(l,l,1,0);

    for (int i = 2; i <= str.size(); i++)
        for (int j=1;j<=9;j++)
            ans += get(j,j,i,1);

    return ans;
}
signed main (){
    ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
    ll a,b;
    cin>>a>>b;
    cout<<G(b) - G(a - 1)<<"\n";
}

Compilation message (stderr)

numbers.cpp: In function 'long long int G(long long int)':
numbers.cpp:58:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |     for (int i = 2; i <= str.size(); i++)
      |                     ~~^~~~~~~~~~~~~

• Subtask 1: 21.25 / 25
• Subtask 2: 75 / 75