Submission #274774

#	Time	Username	Problem	Language	Result	Execution time	Memory
274774		stefantaga	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	5 ms	384 KiB

numbers

#include <bits/stdc++.h>

using namespace std;
long long dp[10][10][20][2];
string str;
//all : all digits are allowed
long long Calc(int first,int second,int len,bool all)
{
    if(len>=str.length())
    {
        return 1;
    }
    else
    {
        if(dp[first][second][len][all]==-1)
        {
            long long help=0;
            if(all)
            {
                for(int n=0; n<=9; n++)
                {
                    if(n!=first&&n!=second)
                    {
                        help+=Calc(second,n,len+1,true);
                    }
                }
            }
            else
            {
                int limit=str[len]-'0';
                for(int n=0; n<limit; n++)
                {
                    if(n!=first&&n!=second)
                    {
                        help+=Calc(second,n,len+1,true);
                    }
                }
                if(limit!=first&&limit!=second)
                {
                    help+=Calc(second,limit,len+1,false);
                }
            }
            dp[first][second][len][all]=help;
        }
        return dp[first][second][len][all];
    }
}
long long Get(long long num)
{
    if(num<0)return 0;
    stringstream ss;
    ss<<num;
    str=ss.str();
    memset(dp,-1,sizeof(dp));
    int first=str[0]-'0';
    long long res=1;
    for(int n=1; n<=first; n++)
    {
        res+=Calc(n,n,1,n!=first);
    }
    for(int k=2; k<=str.length(); k++)
    {
        for(int n=1; n<10; n++)
        {
            res+=Calc(n,n,k,true);
        }
    }
    return res;
}
int main()
{
    #ifdef HOME
    ifstream cin("date.in");
    ofstream cout("date.out");
    #endif // HOME
    long long a,b;
    cin>>a>>b;
    long long counter=Get(b)-Get(a-1);
    cout<<counter;
    return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'long long int Calc(int, int, int, bool)':
numbers.cpp:9:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     if(len>=str.length())
      |        ~~~^~~~~~~~~~~~~~
numbers.cpp: In function 'long long int Get(long long int)':
numbers.cpp:61:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |     for(int k=2; k<=str.length(); k++)
      |                  ~^~~~~~~~~~~~~~

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