abc083_b_some_sums.cpp

// Some Sums | https://atcoder.jp/contests/abc083/tasks/abc083_b
// Time: O(n log n); extra space: O(1).
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>

void solve() {
    int n,a,b,ans=0;
    std::cin>>n>>a>>b;
    for(int i=1;i<=n;++i) {
        int sum=0;
        for(int v=i;v;v/=10)sum+=v%10;
        if(a<=sum&&sum<=b)ans+=i;
    }
    std::cout<<ans<<'\n';
}
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    solve();
}