[Niuke] b-complete square

Preface

Use stl Two points , The best subscript is from 0 Let's start
$tag:$ Two points mathematics
The question :

Ideas :
$l\le x\le r$

$\sqrt{l}\le \sqrt{x}\le \sqrt{r}$

Again because $l,r\le 10^9$ So we can preprocess out $\sqrt{x}$ Array

Finally, determine the square interval by bisection , The size of the square interval is the answer

code :

int a[N];
int i;

void init(){
    
	Fup(i,1,1e5)a[i] = i;
}

void solve(){
    
	int l,r;cin>>l>>r;
	int n = 1e5;
	
	int L =  lower_bound(a+1,a+1+n,sqrt(l)) - a;
	int R =  upper_bound(a+1,a+1+n,sqrt(r)) - a;
	cout<<max(R-L,0)<<endl;
}

int main(){
    
	init();
	
	int t;cin>>t;while(t--)
    solve();
    return 0 ;
}