Submission

Score: 100

User: samsenpisardmoo26

Problemset: J.Nine Khanaphat

Language: cpp

Time: 0.002 second

Submitted On: 2026-10-10 15:37:06

#include <bits/stdc++.h>
using namespace std;
int main()
{
    long long n, m;
    cin >> n >> m;

    long long cnt=0;

    for(long long i=1; i<=m; i*=10)
    {
        long long suf = m/(i*10);
        long long curr = (m/i)%10;
        long long pre = m%i;

        if(curr < 9) cnt += suf*i;
        else cnt += suf*i+pre+1;
    }

    long long cnt2=0;

    for(long long i=1; i<n; i*=10)
    {
        long long suf = (n-1)/(i*10);
        long long curr = ((n-1)/i)%10;
        long long pre = (n-1)%i;

        if(curr < 9) cnt2 += suf*i;
        else cnt2 += suf*i+pre+1;
    }

    cout << cnt-cnt2;
}