#include <bits/stdc++.h> #define ll long long using namespace std; ll a[30],d[30][30][30][2],l,r,i,j,k,t,n,U; ll A(ll x){ memset(d,0,sizeof(d));U=0; string s=to_string(x);n=s.size(); for(i=1;i<=n;i++)a[i]=s[i-1]-'0'; for(j=1;j<=a[1];j++)for(k=0;k<=9&&k!=j;k++) d[2][j][k][0]=(j<a[1]||k<a[2]),d[2][j][k][1]=(j==a[1])*(k==a[2]); for(i=2;i<n;i++)for(j=0;j<=9;j++)for(k=0;k<=9;k++)for(t=0;t<=9;t++) d[i+1][k][t][0]+=(d[i][j][k][0]+d[i][j][k][1]*(t<a[i+1])*(k==a[i]))*(t!=k)*(t!=j)*(k!=j), d[i+1][k][t][1]+=d[i][j][k][1]*(k==a[i])*(t==a[i+1])*(t!=k)*(t!=j)*(k!=j); for(j=0;j<=9;j++)for(k=0;k<=9;k++)U+=d[n][j][k][0]+d[n][j][k][1]; for(i=0;i<n-2;i++)U+=81<<(3*i); if(n<2)return x+1; return U+10; } main(){cin>>l>>r; cout<<A(r)-min(2*l,A(l-1));}

numbers.cpp: In function 'long long int A(long long int)':
numbers.cpp:17:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(n<2)return x+1; return U+10;
  ^~
numbers.cpp:17:21: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(n<2)return x+1; return U+10;
                     ^~~~~~
numbers.cpp: At global scope:
numbers.cpp:19:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){cin>>l>>r; cout<<A(r)-min(2*l,A(l-1));}
      ^