尽量别用 `pow`，用位运算。
by tallnut @ 2024-04-13 21:42:44
@[C20220215](/user/545601) lowbit不快？
```cpp
#include <bits/stdc++.h>
using namespace std;
long long l,r;
int sum=0;
vector<pair<long long,long long>> v;
int main(){
cin >> l >> r;
while(l!=0&&l+(l&(-l))<=r){
v.push_back({l,l+(l&(-l))});
l+=(l&(-l));
}
while(r!=0&&l<=r-(r&(-r))){
v.push_back({r-(r&(-r)),r});
r-=(r&(-r));
}
cout<<v.size()<<endl;
sort(v.begin(),v.end());
for(auto tmp:v){
cout<<tmp.first <<" "<<tmp.second<<endl;
}
return 0;
}
```
by 初星逝者 @ 2024-04-13 22:04:47
@[C20220215](/user/545601) 我记得 pow 精度不够 $2^{60}$
by Fire_flame @ 2024-04-13 22:13:32
@[tallnut](/user/1037586) @[Fire_flame](/user/668869) @[初星逝者](/user/376679) 已过，感谢
by C20220215 @ 2024-04-13 22:23:01