F - Balanced Number

 #include <iostream>
 #include <algorithm>
 #include <cstring>
 #include <cstdio>
 #include <string>
 #include <map>
 #include <cmath>
 #include <vector>

 #define Faster ios::sync_with_stdio(false),cin.tie(0)
 #define Read freopen("in.txt","r",stdin),freopen("out.txt","w",stdout)
 #define Close fclose(stdin),fclose(stdout)
 const int maxn = 1e4 + ;
 using namespace std;
 const int MOD = 1e9+;
 typedef long long ll;

 ll dp[][][];
 int a[];

 ll dfs(int pos, int cut, int sum, bool limit){
     if (pos == -) return sum?:;    //sum为0的时候说明是平衡的
     if (sum < ) return ;    //sum < 0 就肯定不平衡了返回0
     if(!limit && dp[pos][cut][sum] != -)
         return dp[pos][cut][sum];
     int up = limit?a[pos]:;
     ll ans = ;
     for(int i = ; i <= up;i++){
         ans += dfs(pos-, cut, sum + (pos-cut)*i, limit && a[pos] == i);
     }
     if(!limit)
         dp[pos][cut][sum] = ans;
     return ans;
 }

 ll solve(ll x){
     int pos = ;
     while(x){
         a[pos++] = x%;
         x /= ;
     }
     ll ans = ;
     for(int i = ;i < pos;i++){
         ans += dfs(pos-, i, , true);
     }
     return ans - pos + ;
     //因为0多加了(pos - 1)次
 }

 int main(){
     Faster;
     int t;
     cin >> t;
     memset(dp, -, sizeof(dp));
     while(t--){
         ll l, r;
         cin >> l >> r;
         ll ans = solve(r) - solve(l-);
         cout << ans << endl;
     }
     return ;
 }