Submission #162595

---

Source Code Expand

#include <stdio.h>
#include <stdlib.h>

#include <iostream>

#include <string>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;


long long A, B;
long long dp[20];

long long num( long long x )
{
	if ( x < 4 ) return 0;
	if ( x < 9 ) return 1;
	if ( x < 10 ) return 2;

	int md;
	long long c =x;
	long long dnum=0;
	while( c>0 )
	{
		md = c%10;
		c /= 10;
		++dnum;
	}

	const auto kX = dp[dnum-2];
	const auto kNumMd = num(md);
	return kX*(md-kNumMd) + pow(10,dnum-1)*kNumMd;
}

int main()
{

	cin >> A >> B;

	dp[0] = 2;
	long long term =10;
	for( long long i=1; i<20; ++i )
	{
		dp[i] = 2*term + dp[i-1]*8;
		term*=10;
	}

	long long res =num(B)-num(A);

	cout << res << endl;

	return 0;
}

Submission Info

Judge Result